Through the Interface

Transforming a list of RegAppIds from XML to HTML using XSLT

As raised as a possibility at the end of the last post, I did choose to throw together a quick XSLT stylesheet to generate an HTML report of the XML data created by our XRA command.

To enable this I did make a few changes to our command implementation, which we’ll take a look at first.

Here’s the updated C# code, with new/modified lines in red (and here’s the updated source file):

    1 using Autodesk.AutoCAD.ApplicationServices;

    2 using Autodesk.AutoCAD.DatabaseServices;

    3 using Autodesk.AutoCAD.EditorInput;

    4 using Autodesk.AutoCAD.Runtime;

    5 using System.Collections.Generic;

    6 using System.Text;

    7 using System.Xml;

    8 using System.Xml.Serialization;

    9 using System.IO;

   10 using System;

   11 

   12 namespace XrefRegApps

   13 {

   14   [XmlRoot("RegAppData")]

   15   public class RegAppData

   16   {

   17     // The name of our drawing

   18 

   19     private string _name;

   20 

   21     [XmlAttribute("Name")]

   22     public string Name

   23     {

   24       get { return _name; }

   25       set { _name = value; }

   26     }

   27 

   28     // The location of our drawing

   29 

   30     private string _dwg;

   31 

   32     [XmlAttribute("File")]

   33     public string File

   34     {

   35       get { return _dwg; }

   36       set { _dwg = value; }

   37     }

   38 

   39     private string _dwgVersion;

   40 

   41     [XmlAttribute("DwgVersion")]

   42     public string DwgVersion

   43     {

   44       get { return _dwgVersion; }

   45       set { _dwgVersion = value; }

   46     }

   47 

   48     // The list of our drawing's Registered Application IDs

   49 

   50     private List<string> _regAppIds = new List<string>();

   51 

   52     [XmlArrayItem("RegAppId")]

   53     public List<string> RegAppIds

   54     {

   55       get { return _regAppIds; }

   56       set { _regAppIds = value; }

   57     }

   58 

   59     public void AddRegAppId(string id)

   60     {

   61       if (!_regAppIds.Contains(id))

   62         _regAppIds.Add(id);

   63     }

   64   }

   65 

   66   public class Commands

   67   {

   68     private const string regAppDataXml = "c:\\RegAppData.xml";

   69 

   70     private void SerializeRegAppData(

   71       Dictionary<string, RegAppData> dict

   72     )

   73     {

   74       if (dict.Count > 0)

   75       {

   76         // No direct way to serialize a dictionary to XML,

   77         // so we'll create a list from it and serialize that

   78 

   79         List<RegAppData> regData =

   80           new List<RegAppData>(dict.Count);

   81         foreach (KeyValuePair<string, RegAppData> kv in dict)

   82         {

   83           regData.Add(kv.Value);

   84         }

   85 

   86         // Serialize our list to the specified XML file

   87 

   88         XmlSerializer xs =

   89           new XmlSerializer(typeof(List<RegAppData>));

   90         XmlTextWriter xw =

   91           new XmlTextWriter(regAppDataXml, Encoding.UTF8);

   92         xw.WriteProcessingInstruction(

   93           "xml-stylesheet",

   94           "type=\"text/xsl\" href=\"RegAppData.xslt\""

   95         );

   96         xs.Serialize(xw, regData);

   97         xw.Close();

   98       }

   99     }

  100 

  101     // Read and return the previous Registered Application data

  102     // from our stored XML file

  103 

  104     private Dictionary<string, RegAppData>

  105       DeserializeRegAppData()

  106     {

  107       if (File.Exists(regAppDataXml))

  108       {

  109         XmlSerializer xs =

  110           new XmlSerializer(typeof(List<RegAppData>));

  111         XmlTextReader xr = new XmlTextReader(regAppDataXml);

  112         if (xs.CanDeserialize(xr))

  113         {

  114           // No direct way to serialize a dictionary to XML,

  115           // so we'll read a list and populate a dictionary

  116           // from it

  117 

  118           List<RegAppData> regData =

  119             (List<RegAppData>)xs.Deserialize(xr);

  120           xr.Close();

  121           Dictionary<string, RegAppData> dict =

  122             new Dictionary<string, RegAppData>();

  123           foreach (RegAppData rad in regData)

  124           {

  125             dict.Add(rad.File, rad);

  126           }

  127           return dict;

  128         }

  129       }

  130       return new Dictionary<string, RegAppData>();

  131     }

  132 

  133     [CommandMethod("XRA")]

  134     public void ExternalReferenceRegisteredApps()

  135     {

  136       Document doc =

  137           Application.DocumentManager.MdiActiveDocument;

  138       Database db = doc.Database;

  139       Editor ed = doc.Editor;

  140 

  141       // Prompt the user for the path to a DWG to test

  142 

  143       PromptStringOptions pso =

  144         new PromptStringOptions(

  145           "\nEnter path to root drawing file: "

  146         );

  147       pso.AllowSpaces = true;

  148       PromptResult pr = ed.GetString(pso);

  149       if (pr.Status != PromptStatus.OK)

  150         return;

  151 

  152       if (!File.Exists(pr.StringResult))

  153       {

  154         ed.WriteMessage("\nFile does not exist.");

  155         return;

  156       }

  157 

  158       try

  159       {

  160         // We start by reading any existing RegApp data

  161         // from XML

  162 

  163         Dictionary<string, RegAppData> regData =

  164           DeserializeRegAppData();

  165 

  166         // Load the DWG into a side database

  167 

  168         Database mainDb = new Database(false, true);

  169         using (mainDb)

  170         {

  171           mainDb.ReadDwgFile(

  172             pr.StringResult,

  173             FileOpenMode.OpenForReadAndAllShare,

  174             true,

  175             null

  176           );

  177 

  178           // We need an additional step to resolve Xrefs

  179 

  180           mainDb.ResolveXrefs(false, false);

  181 

  182           // Get the XrefGraph for the specified database

  183 

  184           XrefGraph xg = mainDb.GetHostDwgXrefGraph(true);

  185 

  186           // Loop through the nodes in the graph

  187 

  188           for (int i = 0; i < xg.NumNodes; i++)

  189           {

  190             // Get each node and check its status

  191 

  192             XrefGraphNode xgn = xg.GetXrefNode(i);

  193 

  194             switch (xgn.XrefStatus)

  195             {

  196               // If Un*, print a message

  197 

  198               case XrefStatus.Unresolved:

  199                 ed.WriteMessage(

  200                   "\nUnresolved xref \"{0}\"", xgn.Name

  201                 );

  202                 break;

  203               case XrefStatus.Unloaded:

  204                 ed.WriteMessage(

  205                   "\nUnloaded xref \"{0}\"", xgn.Name

  206                 );

  207                 break;

  208               case XrefStatus.Unreferenced:

  209                 ed.WriteMessage(

  210                   "\nUnreferenced xref \"{0}\"", xgn.Name

  211                 );

  212                 break;

  213               case XrefStatus.Resolved:

  214                 {

  215                   // If Resolved, get the RegAppTable

  216 

  217                   Database xdb = xgn.Database;

  218                   if (xdb != null)

  219                   {

  220                     Transaction tr =

  221                     xdb.TransactionManager.StartTransaction();

  222                     using (tr)

  223                     {

  224                       RegAppTable rat =

  225                         (RegAppTable)tr.GetObject(

  226                           xdb.RegAppTableId,

  227                           OpenMode.ForRead

  228                         );

  229 

  230                       // We'll store our RegApp data in an

  231                       // object

  232 

  233                       RegAppData dwgData = new RegAppData();

  234                       dwgData.Name =

  235                         (i == 0 ?

  236                           Path.GetFileNameWithoutExtension(

  237                             xgn.Name

  238                           ) :

  239                           xgn.Name

  240                         );

  241                       dwgData.File = xdb.Filename;

  242                       dwgData.DwgVersion =

  243                         xdb.OriginalFileVersion.ToString();

  244 

  245                       // Collect the contained names of the

  246                       // RegAppTableRecords (the RegAppIds)

  247                       // in a list

  248 

  249                       foreach (ObjectId id in rat)

  250                       {

  251                         RegAppTableRecord ratr =

  252                           (RegAppTableRecord)tr.GetObject(

  253                             id,

  254                             OpenMode.ForRead

  255                           );

  256                         dwgData.AddRegAppId(ratr.Name);

  257                       }

  258 

  259                       // Store the object in our dictionary,

  260                       // replacing any existing item

  261                       // (keyed off the entire DWG path, not

  262                       // just the name)

  263 

  264                       if (regData.ContainsKey(dwgData.File))

  265                         regData.Remove(dwgData.File);

  266                       regData.Add(dwgData.File, dwgData);

  267 

  268                       // Print the drawing information

  269                       // and the RegAppId count

  270 

  271                       ed.WriteMessage(

  272                         "\nDrawing \"{0}\" (\"{1}\") with " +

  273                         "{2} RegAppIds",

  274                         dwgData.Name,

  275                         dwgData.File,

  276                         dwgData.RegAppIds.Count

  277                       );

  278 

  279                       // Even if only reading, commit the

  280                       // transaction (it's cheaper than

  281                       // aborting)

  282 

  283                       tr.Commit();

  284                     }

  285                   }

  286                   break;

  287                 }

  288             }

  289           }

  290           // Save our data to XML

  291 

  292           SerializeRegAppData(regData);

  293         }

  294       }

  295       catch (System.Exception ex)

  296       {

  297         ed.WriteMessage(

  298           "\nProblem reading/processing \"{0}\": {1}",

  299           pr.StringResult, ex.Message

  300         );

  301       }

  302     }

  303   }

  304 }

The changes are very minor: we’ve added a DwgVersion attribute to our XML, as well as adjusting the save type of RegAppIds from being a simple string attribute to an array of elements (which allows us to determine the number of RegAppIds per drawing more easily).

We've hardcoded the path of the XML file to C:\ (feel free to change this, of course), as well as writing a stylesheet reference directly into the XML to just let the browser take care of the transformation to HTML.

Speaking of the stylesheet, here’s the RegAppData.xslt file to be placed alongside the XML output (currently in C:\, as just mentioned):

<?xml version="1.0" encoding="utf-8"?>

<xsl:stylesheet

  version="1.0"

  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"

>

  <xsl:output method="html" indent="yes" version="4.0"/>

 

  <xsl:template match="ArrayOfRegAppData">

    <h2>Registered application IDs per drawing</h2>

    <table>

      <tr>

        <td><em>Drawing name</em></td>

        <td>

          <em>Number of RegAppIds</em>

        </td>

      </tr>

      <xsl:apply-templates select="*"/>

    </table>

  </xsl:template>

 

  <xsl:template match="RegAppData">

    <tr>

      <td>

        <b>

          <xsl:attribute name="Title">

            <xsl:value-of select="@File"/>

            <xsl:text> (</xsl:text>

            <xsl:value-of select="@DwgVersion"/>

            <xsl:text>)</xsl:text>

          </xsl:attribute>

          <xsl:value-of select="@Name"/>

        </b>

      </td>

      <td>

        <xsl:attribute name="Title">

          <xsl:for-each select="RegAppIds/RegAppId">

            <xsl:value-of select="node()"/>

            <xsl:if test="position() != last()">

              <xsl:text>&#x0A;</xsl:text>

            </xsl:if>

          </xsl:for-each>

        </xsl:attribute>

        <center>

          <xsl:value-of select="count(RegAppIds/RegAppId)"/>

        </center>

      </td>

    </tr>

  </xsl:template>

</xsl:stylesheet>

The stylesheet is also quite simple: it creates an HTML file containing a table of two columns – one with the names of our drawings (with the path and version in a tooltip) and the number of RegAppIds found in that drawing (with the specific names in a tooltip). We’ll see that in action a bit.

Running the XRA command just as we did in the last post, we should see this kind of XML output:

<?xml-stylesheet type="text/xsl" href="RegAppData.xslt"?>

<ArrayOfRegAppData

  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

  xmlns:xsd="http://www.w3.org/2001/XMLSchema">

  <RegAppData

    Name="A-01"

    File="C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Architectural\A-01.dwg"

    DwgVersion="Current">

    <RegAppIds>

      <RegAppId>ACAD</RegAppId>

      <RegAppId>CONTENTBLOCKDESCRIPTION</RegAppId>

      <RegAppId>CONTENTBLOCKICON</RegAppId>

      <RegAppId>CONTENTTABDATA</RegAppId>

      <RegAppId>CONTENTCURRENTTAB</RegAppId>

      <RegAppId>ACAD_PSEXT</RegAppId>

      <RegAppId>PE_URL</RegAppId>

      <RegAppId>RAK</RegAppId>

      <RegAppId>AcAecLayerStandard</RegAppId>

      <RegAppId>ACAD_DSTYLE_DIMTEXT_FILL</RegAppId>

      <RegAppId>ACAD_EXEMPT_FROM_CAD_STANDARDS</RegAppId>

      <RegAppId>AcDbBlockRepETag</RegAppId>

      <RegAppId>AcDbDynamicBlockTrueName</RegAppId>

      <RegAppId>AcDbDynamicBlockGUID</RegAppId>

      <RegAppId>AcDbBlockRepBTag</RegAppId>

      <RegAppId>ACAD_DSTYLE_DIMEXT_LENGTH</RegAppId>

      <RegAppId>ACAD_DSTYLE_DIMEXT_ENABLED</RegAppId>

      <RegAppId>ACAD_DSTYLE_DIM_LINETYPE</RegAppId>

      <RegAppId>ACAD_DSTYLE_DIM_EXT1_LINETYPE</RegAppId>

      <RegAppId>ACAD_DSTYLE_DIM_EXT2_LINETYPE</RegAppId>

      <RegAppId>ACAD_MLEADERVER</RegAppId>

    </RegAppIds>

  </RegAppData>

  <RegAppData

    Name="Grid Plan"

    File="C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Architectural\Res\Grid Plan.dwg"

    DwgVersion="AC1021">

    <RegAppIds>

      <RegAppId>ACAD</RegAppId>

      <RegAppId>CONTENTBLOCKDESCRIPTION</RegAppId>

      <RegAppId>CONTENTBLOCKICON</RegAppId>

      <RegAppId>CONTENTTABDATA</RegAppId>

      <RegAppId>CONTENTCURRENTTAB</RegAppId>

      <RegAppId>ACAD_PSEXT</RegAppId>

      <RegAppId>ACAD_DSTYLE_DIMTEXT_FILL</RegAppId>

    </RegAppIds>

  </RegAppData>

  <RegAppData

    Name="Wall Base"

    File="C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Architectural\Res\Wall Base.dwg"

    DwgVersion="AC1021">

    <RegAppIds>

      <RegAppId>ACAD</RegAppId>

      <RegAppId>CONTENTBLOCKDESCRIPTION</RegAppId>

      <RegAppId>CONTENTBLOCKICON</RegAppId>

      <RegAppId>CONTENTTABDATA</RegAppId>

      <RegAppId>CONTENTCURRENTTAB</RegAppId>

      <RegAppId>RAK</RegAppId>

      <RegAppId>AcAecLayerStandard</RegAppId>

      <RegAppId>ACAD_PSEXT</RegAppId>

      <RegAppId>PE_URL</RegAppId>

      <RegAppId>ACAD_DSTYLE_DIMTEXT_FILL</RegAppId>

      <RegAppId>ACAD_MLEADERVER</RegAppId>

    </RegAppIds>

  </RegAppData>

  <RegAppData

    Name="Master Site Plan"

    File="C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Civil\Master Site Plan.dwg"

    DwgVersion="AC1021">

    <RegAppIds>

      <RegAppId>ACAD</RegAppId>

      <RegAppId>RAK</RegAppId>

      <RegAppId>DCA_FIGURE_XENT</RegAppId>

      <RegAppId>ADE</RegAppId>

      <RegAppId>ALIGNMENT_DB_APP</RegAppId>

      <RegAppId>SDI_PROFILE</RegAppId>

      <RegAppId>SDSK_POINT</RegAppId>

      <RegAppId>SVPLINE</RegAppId>

      <RegAppId>ADCADD_ZZ</RegAppId>

      <RegAppId>SDSK_PMN</RegAppId>

      <RegAppId>CIVIL_DRAFT</RegAppId>

      <RegAppId>CIVIL_LINE_TABLE</RegAppId>

      <RegAppId>CIVIL_CURVE_TABLE</RegAppId>

      <RegAppId>CIVIL_SPIRAL_TABLE</RegAppId>

      <RegAppId>SDI_XSECTIONS</RegAppId>

      <RegAppId>ACAD_PSEXT</RegAppId>

      <RegAppId>ACAD_MLEADERVER</RegAppId>

      <RegAppId>DCO15</RegAppId>

    </RegAppIds>

  </RegAppData>

  <RegAppData

    Name="PB-BASE"

    File="C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Civil\PB-BASE.dwg"

    DwgVersion="AC1021">

    <RegAppIds>

      <RegAppId>ACAD</RegAppId>

      <RegAppId>RAK</RegAppId>

      <RegAppId>DCA_FIGURE_XENT</RegAppId>

      <RegAppId>ALIGNMENT_DB_APP</RegAppId>

      <RegAppId>SDI_PROFILE</RegAppId>

      <RegAppId>ACAD_PSEXT</RegAppId>

      <RegAppId>ACAD_MLEADERVER</RegAppId>

    </RegAppIds>

  </RegAppData>

  <RegAppData

    Name="PB-EX41"

    File="C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Civil\PB-EX41.dwg"

    DwgVersion="AC1021">

    <RegAppIds>

      <RegAppId>ACAD</RegAppId>

      <RegAppId>SDSK_POINT</RegAppId>

      <RegAppId>SVPLINE</RegAppId>

      <RegAppId>ACAD_PSEXT</RegAppId>

      <RegAppId>DCO15</RegAppId>

      <RegAppId>ACAD_MLEADERVER</RegAppId>

    </RegAppIds>

  </RegAppData>

  <RegAppData

    Name="PB-EX61"

    File="C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Civil\PB-EX61.dwg"

    DwgVersion="AC1021">

    <RegAppIds>

      <RegAppId>ACAD</RegAppId>

      <RegAppId>SVPLINE</RegAppId>

      <RegAppId>ACAD_PSEXT</RegAppId>

      <RegAppId>DCO15</RegAppId>

      <RegAppId>ACAD_MLEADERVER</RegAppId>

    </RegAppIds>

  </RegAppData>

</ArrayOfRegAppData>

Which, when loaded into a browser, should be displayed like this:

As we hover over the name of a drawing in which we’re interested, we see its path and drawing version:

And as we hover over the RegAppId count, we see the names of the individual IDs:

That’s it for this post. We’ll wrap this series up by making some modifications to ScriptPro 2.0 in the next post.

Persisting RegAppId data from an external AutoCAD drawing to XML using .NET

This post takes the code from the last post and extends it to serialize the collected RegAppId data to an XML file, as per Step 3 below:

1. Implement a command to collect RegAppId information for the active document
2. Extend this command to work on a drawing not loaded in the editor
3. Save our RegAppId information to some persistent location (XML)
4. Create a modified version of ScriptPro 2.0 (one of our Plugins of the Month) to call our command without opening the drawing

I’ve chosen once again to leverage the very handy XmlSerializer class to handle serialization to and from XML: all we have to do is get our data in a data structure with appropriate metadata and the rest is taken care of by .NET. More or less, anyway. :-)

Here’s the updated code, with the new/modified lines in red (and here’s the updated source file):

    1 using Autodesk.AutoCAD.ApplicationServices;

    2 using Autodesk.AutoCAD.DatabaseServices;

    3 using Autodesk.AutoCAD.EditorInput;

    4 using Autodesk.AutoCAD.Runtime;

    5 using System.Collections.Generic;

    6 using System.Text;

    7 using System.Xml;

    8 using System.Xml.Serialization;

    9 using System.IO;

   10 using System;

   11 

   12 namespace XrefRegApps

   13 {

   14   [XmlRoot("RegAppData")]

   15   public class RegAppData

   16   {

   17     // The name of our drawing

   18 

   19     private string _name;

   20 

   21     [XmlAttribute("Name")]

   22     public string Name

   23     {

   24       get { return _name; }

   25       set { _name = value; }

   26     }

   27 

   28     // The location of our drawing

   29 

   30     private string _dwg;

   31 

   32     [XmlAttribute("File")]

   33     public string File

   34     {

   35       get { return _dwg; }

   36       set { _dwg = value; }

   37     }

   38 

   39     // The list of our drawing's Registered Application IDs

   40 

   41     private List<string> _regAppIds = new List<string>();

   42 

   43     [XmlAttribute("RegAppIds")]

   44     public List<string> RegAppIds

   45     {

   46       get { return _regAppIds; }

   47       set { _regAppIds = value; }

   48     }

   49 

   50     public void AddRegAppId(string id)

   51     {

   52       if (!_regAppIds.Contains(id))

   53         _regAppIds.Add(id);

   54     }

   55   }

   56 

   57   public class Commands

   58   {

   59     private const string regAppDataXml = "RegAppData.xml";

   60 

   61     private void SerializeRegAppData(

   62       Dictionary<string, RegAppData> dict

   63     )

   64     {

   65       if (dict.Count > 0)

   66       {

   67         // No direct way to serialize a dictionary to XML,

   68         // so we'll create a list from it and serialize that

   69 

   70         List<RegAppData> regData =

   71           new List<RegAppData>(dict.Count);

   72         foreach (KeyValuePair<string, RegAppData> kv in dict)

   73         {

   74           regData.Add(kv.Value);

   75         }

   76 

   77         // Serialize our list to the specified XML file

   78 

   79         XmlSerializer xs =

   80           new XmlSerializer(typeof(List<RegAppData>));

   81         XmlTextWriter xw =

   82           new XmlTextWriter(regAppDataXml, Encoding.UTF8);

   83         xs.Serialize(xw, regData);

   84         xw.Close();

   85       }

   86     }

   87 

   88     // Read and return the previous Registered Application data

   89     // from our stored XML file

   90 

   91     private Dictionary<string, RegAppData>

   92       DeserializeRegAppData()

   93     {

   94       if (File.Exists(regAppDataXml))

   95       {

   96         XmlSerializer xs =

   97           new XmlSerializer(typeof(List<RegAppData>));

   98         XmlTextReader xr = new XmlTextReader(regAppDataXml);

   99         if (xs.CanDeserialize(xr))

  100         {

  101           // No direct way to serialize a dictionary to XML,

  102           // so we'll read a list and populate a dictionary

  103           // from it

  104 

  105           List<RegAppData> regData =

  106             (List<RegAppData>)xs.Deserialize(xr);

  107           xr.Close();

  108           Dictionary<string, RegAppData> dict =

  109             new Dictionary<string, RegAppData>();

  110           foreach (RegAppData rad in regData)

  111           {

  112             dict.Add(rad.File, rad);

  113           }

  114           return dict;

  115         }

  116       }

  117       return new Dictionary<string, RegAppData>();

  118     }

  119 

  120     [CommandMethod("XRA")]

  121     public void ExternalReferenceRegisteredApps()

  122     {

  123       Document doc =

  124           Application.DocumentManager.MdiActiveDocument;

  125       Database db = doc.Database;

  126       Editor ed = doc.Editor;

  127 

  128       // Prompt the user for the path to a DWG to test

  129 

  130       PromptStringOptions pso =

  131         new PromptStringOptions(

  132           "\nEnter path to root drawing file: "

  133         );

  134       pso.AllowSpaces = true;

  135       PromptResult pr = ed.GetString(pso);

  136       if (pr.Status != PromptStatus.OK)

  137         return;

  138 

  139       if (!File.Exists(pr.StringResult))

  140       {

  141         ed.WriteMessage("\nFile does not exist.");

  142         return;

  143       }

  144 

  145       try

  146       {

  147         // We start by reading any existing RegApp data

  148         // from XML

  149 

  150         Dictionary<string, RegAppData> regData =

  151           DeserializeRegAppData();

  152 

  153         // Load the DWG into a side database

  154 

  155         Database mainDb = new Database(false, true);

  156         using (mainDb)

  157         {

  158           mainDb.ReadDwgFile(

  159             pr.StringResult,

  160             FileOpenMode.OpenForReadAndAllShare,

  161             true,

  162             null

  163           );

  164 

  165           // We need an additional step to resolve Xrefs

  166 

  167           mainDb.ResolveXrefs(false, false);

  168 

  169           // Get the XrefGraph for the specified database

  170 

  171           XrefGraph xg = mainDb.GetHostDwgXrefGraph(true);

  172 

  173           // Loop through the nodes in the graph

  174 

  175           for (int i = 0; i < xg.NumNodes; i++)

  176           {

  177             // Get each node and check its status

  178 

  179             XrefGraphNode xgn = xg.GetXrefNode(i);

  180 

  181             switch (xgn.XrefStatus)

  182             {

  183               // If Un*, print a message

  184 

  185               case XrefStatus.Unresolved:

  186                 ed.WriteMessage(

  187                   "\nUnresolved xref \"{0}\"", xgn.Name

  188                 );

  189                 break;

  190               case XrefStatus.Unloaded:

  191                 ed.WriteMessage(

  192                   "\nUnloaded xref \"{0}\"", xgn.Name

  193                 );

  194                 break;

  195               case XrefStatus.Unreferenced:

  196                 ed.WriteMessage(

  197                   "\nUnreferenced xref \"{0}\"", xgn.Name

  198                 );

  199                 break;

  200               case XrefStatus.Resolved:

  201                 {

  202                   // If Resolved, get the RegAppTable

  203 

  204                   Database xdb = xgn.Database;

  205                   if (xdb != null)

  206                   {

  207                     Transaction tr =

  208                     xdb.TransactionManager.StartTransaction();

  209                     using (tr)

  210                     {

  211                       RegAppTable rat =

  212                         (RegAppTable)tr.GetObject(

  213                           xdb.RegAppTableId,

  214                           OpenMode.ForRead

  215                         );

  216 

  217                       // We'll store our RegApp data in an

  218                       // object

  219 

  220                       RegAppData dwgData = new RegAppData();

  221                       dwgData.Name =

  222                         (i == 0 ?

  223                           Path.GetFileNameWithoutExtension(

  224                             xgn.Name

  225                           ) :

  226                           xgn.Name

  227                         );

  228                       dwgData.File = xdb.Filename;

  229 

  230                       // Collect the contained names of the

  231                       // RegAppTableRecords (the RegAppIds)

  232                       // in a list

  233 

  234                       foreach (ObjectId id in rat)

  235                       {

  236                         RegAppTableRecord ratr =

  237                           (RegAppTableRecord)tr.GetObject(

  238                             id,

  239                             OpenMode.ForRead

  240                           );

  241                         dwgData.AddRegAppId(ratr.Name);

  242                       }

  243 

  244                       // Store the object in our dictionary,

  245                       // replacing any existing item

  246                       // (keyed off the entire DWG path, not

  247                       // just the name)

  248 

  249                       if (regData.ContainsKey(dwgData.File))

  250                         regData.Remove(dwgData.File);

  251                       regData.Add(dwgData.File, dwgData);

  252 

  253                       // Print the drawing information

  254                       // and the RegAppId count

  255 

  256                       ed.WriteMessage(

  257                         "\nDrawing \"{0}\" (\"{1}\") with " +

  258                         "{2} RegAppIds",

  259                         dwgData.Name,

  260                         dwgData.File,

  261                         dwgData.RegAppIds.Count

  262                       );

  263 

  264                       // Even if only reading, commit the

  265                       // transaction (it's cheaper than

  266                       // aborting)

  267 

  268                       tr.Commit();

  269                     }

  270                   }

  271                   break;

  272                 }

  273             }

  274           }

  275           // Save our data to XML

  276 

  277           SerializeRegAppData(regData);

  278         }

  279       }

  280       catch (System.Exception ex)

  281       {

  282         ed.WriteMessage(

  283           "\nProblem reading/processing \"{0}\": {1}",

  284           pr.StringResult, ex.Message

  285         );

  286       }

  287     }

  288   }

  289 }

When we first run the XRA command with our Civil sample file, we see the contents of the XML file (which seems to be written to the current directory – we could easily hardcode another location, of course) are:

  <?xml version="1.0" encoding="utf-8" ?>

- <ArrayOfRegAppData xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">

  <RegAppData Name="Master Site Plan" File="C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Civil\Master Site Plan.dwg" RegAppIds="ACAD RAK DCA_FIGURE_XENT ADE ALIGNMENT_DB_APP SDI_PROFILE SDSK_POINT SVPLINE ADCADD_ZZ SDSK_PMN CIVIL_DRAFT CIVIL_LINE_TABLE CIVIL_CURVE_TABLE CIVIL_SPIRAL_TABLE SDI_XSECTIONS ACAD_PSEXT ACAD_MLEADERVER DCO15" />

  <RegAppData Name="PB-BASE" File="C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Civil\PB-BASE.dwg" RegAppIds="ACAD RAK DCA_FIGURE_XENT ALIGNMENT_DB_APP SDI_PROFILE ACAD_PSEXT ACAD_MLEADERVER" />

  <RegAppData Name="PB-EX41" File="C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Civil\PB-EX41.dwg" RegAppIds="ACAD SDSK_POINT SVPLINE ACAD_PSEXT DCO15 ACAD_MLEADERVER" />

  <RegAppData Name="PB-EX61" File="C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Civil\PB-EX61.dwg" RegAppIds="ACAD SVPLINE ACAD_PSEXT DCO15 ACAD_MLEADERVER" />

  </ArrayOfRegAppData>

if we run the XRA command again, this time specifying a file from the Architectural sample:

Command: XRA

Enter path to root drawing file: C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Architectural\A-01.dwg

Drawing "A-01" ("C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Architectural\A-01.dwg") with 21 RegAppIds

Drawing "Grid Plan" ("C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Architectural\Res\Grid Plan.dwg") with 7 RegAppIds

Drawing "Wall Base" ("C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Architectural\Res\Wall Base.dwg") with 11 RegAppIds

We will see the XML now contains additional entries:

  <?xml version="1.0" encoding="utf-8" ?>

- <ArrayOfRegAppData xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">

  <RegAppData Name="Master Site Plan" File="C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Civil\Master Site Plan.dwg" RegAppIds="ACAD RAK DCA_FIGURE_XENT ADE ALIGNMENT_DB_APP SDI_PROFILE SDSK_POINT SVPLINE ADCADD_ZZ SDSK_PMN CIVIL_DRAFT CIVIL_LINE_TABLE CIVIL_CURVE_TABLE CIVIL_SPIRAL_TABLE SDI_XSECTIONS ACAD_PSEXT ACAD_MLEADERVER DCO15" />

  <RegAppData Name="PB-BASE" File="C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Civil\PB-BASE.dwg" RegAppIds="ACAD RAK DCA_FIGURE_XENT ALIGNMENT_DB_APP SDI_PROFILE ACAD_PSEXT ACAD_MLEADERVER" />

  <RegAppData Name="PB-EX41" File="C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Civil\PB-EX41.dwg" RegAppIds="ACAD SDSK_POINT SVPLINE ACAD_PSEXT DCO15 ACAD_MLEADERVER" />

  <RegAppData Name="PB-EX61" File="C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Civil\PB-EX61.dwg" RegAppIds="ACAD SVPLINE ACAD_PSEXT DCO15 ACAD_MLEADERVER" />

  <RegAppData Name="A-01" File="C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Architectural\A-01.dwg" RegAppIds="ACAD CONTENTBLOCKDESCRIPTION CONTENTBLOCKICON CONTENTTABDATA CONTENTCURRENTTAB ACAD_PSEXT PE_URL RAK AcAecLayerStandard ACAD_DSTYLE_DIMTEXT_FILL ACAD_EXEMPT_FROM_CAD_STANDARDS AcDbBlockRepETag AcDbDynamicBlockTrueName AcDbDynamicBlockGUID AcDbBlockRepBTag ACAD_DSTYLE_DIMEXT_LENGTH ACAD_DSTYLE_DIMEXT_ENABLED ACAD_DSTYLE_DIM_LINETYPE ACAD_DSTYLE_DIM_EXT1_LINETYPE ACAD_DSTYLE_DIM_EXT2_LINETYPE ACAD_MLEADERVER" />

  <RegAppData Name="Grid Plan" File="C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Architectural\Res\Grid Plan.dwg" RegAppIds="ACAD CONTENTBLOCKDESCRIPTION CONTENTBLOCKICON CONTENTTABDATA CONTENTCURRENTTAB ACAD_PSEXT ACAD_DSTYLE_DIMTEXT_FILL" />

  <RegAppData Name="Wall Base" File="C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Architectural\Res\Wall Base.dwg" RegAppIds="ACAD CONTENTBLOCKDESCRIPTION CONTENTBLOCKICON CONTENTTABDATA CONTENTCURRENTTAB RAK AcAecLayerStandard ACAD_PSEXT PE_URL ACAD_DSTYLE_DIMTEXT_FILL ACAD_MLEADERVER" />

  </ArrayOfRegAppData>

This is really a reasonably simple way of storing our data: it should be trivial to add additional data to the XML, such as the version of the DWG, an entry holding the number of entries in the RegAppId list (although we do have the list itself).

In the next post we may move on to modifying ScriptPro 2.0, but we may take a quick detour and put together an XML stylesheet to visualize the data – let’s see next week.

Counting the RegAppIds for a specific AutoCAD drawing and its external references using .NET

This post extends the code shown in the last – very similarly named – post, to work on a specified drawing, that – very importantly – does not get loaded into the AutoCAD editor. Step 2 in the list for this series:

1. Implement a command to collect RegAppId information for the active document
2. Extend this command to work on a drawing not loaded in the editor
3. Save our RegAppId information to some persistent location (XML)
4. Create a modified version of ScriptPro 2.0 (one of our Plugins of the Month) to call our command without opening the drawing

The code starts by prompting the user for the path to the main drawing to load (which will eventually be provided by the modified ScriptPro 2.0 application, so no need to use a dialog), before attempting to load the file into a side database and resolve any xrefs it contains. The main loop is as before with a new catch statement taking care of any exceptions thrown during drawing load.

Here’s the updated C# code, with modified lines in red (and here’s the updated source file):

    1 using Autodesk.AutoCAD.ApplicationServices;

    2 using Autodesk.AutoCAD.DatabaseServices;

    3 using Autodesk.AutoCAD.EditorInput;

    4 using Autodesk.AutoCAD.Runtime;

    5 using System.Collections.Generic;

    6 using System.IO;

    7 using System;

    8 

    9 namespace XrefRegApps

   10 {

   11   public class Commands

   12   {

   13     [CommandMethod("XRA")]

   14     public void ExternalReferenceRegisteredApps()

   15     {

   16       Document doc =

   17           Application.DocumentManager.MdiActiveDocument;

   18       Database db = doc.Database;

   19       Editor ed = doc.Editor;

   20 

   21       // Prompt the user for the path to a DWG to test

   22 

   23       PromptStringOptions pso =

   24         new PromptStringOptions(

   25           "\nEnter path to root drawing file: "

   26         );

   27       pso.AllowSpaces = true;

   28       PromptResult pr = ed.GetString(pso);

   29       if (pr.Status != PromptStatus.OK)

   30         return;

   31 

   32       if (!File.Exists(pr.StringResult))

   33       {

   34         ed.WriteMessage("\nFile does not exist.");

   35         return;

   36       }

   37 

   38       try

   39       {

   40         // Load the DWG into a side database

   41 

   42         Database mainDb = new Database(false, true);

   43         using (mainDb)

   44         {

   45           mainDb.ReadDwgFile(

   46             pr.StringResult,

   47             FileOpenMode.OpenForReadAndAllShare,

   48             true,

   49             null

   50           );

   51 

   52           // We need an additional step to resolve Xrefs

   53 

   54           mainDb.ResolveXrefs(false, false);

   55 

   56           // Get the XrefGraph for the specified database

   57 

   58           XrefGraph xg = mainDb.GetHostDwgXrefGraph(true);

   59 

   60           // Loop through the nodes in the graph

   61 

   62           for (int i = 0; i < xg.NumNodes; i++)

   63           {

   64             // Get each node and check its status

   65 

   66             XrefGraphNode xgn = xg.GetXrefNode(i);

   67 

   68             switch (xgn.XrefStatus)

   69             {

   70               // If Un*, print a message

   71 

   72               case XrefStatus.Unresolved:

   73                 ed.WriteMessage(

   74                   "\nUnresolved xref \"{0}\"", xgn.Name

   75                 );

   76                 break;

   77               case XrefStatus.Unloaded:

   78                 ed.WriteMessage(

   79                   "\nUnloaded xref \"{0}\"", xgn.Name

   80                 );

   81                 break;

   82               case XrefStatus.Unreferenced:

   83                 ed.WriteMessage(

   84                   "\nUnreferenced xref \"{0}\"", xgn.Name

   85                 );

   86                 break;

   87               case XrefStatus.Resolved:

   88               {

   89                 // If Resolved, get the RegAppTable

   90 

   91                 Database xdb = xgn.Database;

   92                 if (xdb != null)

   93                 {

   94                   Transaction tr =

   95                     xdb.TransactionManager.StartTransaction();

   96                   using (tr)

   97                   {

   98                     RegAppTable rat =

   99                       (RegAppTable)tr.GetObject(

  100                         xdb.RegAppTableId,

  101                         OpenMode.ForRead

  102                       );

  103 

  104                     // Collect the contained RegAppTableRecord

  105                     // names (i.e. the RegAppIds) in a list

  106 

  107                     List<String> ratIds = new List<string>();

  108                     foreach (ObjectId id in rat)

  109                     {

  110                       RegAppTableRecord ratr =

  111                         (RegAppTableRecord)tr.GetObject(

  112                           id,

  113                           OpenMode.ForRead

  114                         );

  115                       ratIds.Add(ratr.Name);

  116                     }

  117 

  118                     // Print the drawing information

  119                     // and the RegAppId count

  120 

  121                     ed.WriteMessage(

  122                       "\nDrawing \"{0}\" (\"{1}\") with {2}" +

  123                       " RegAppIds",

  124                       xgn.Name,

  125                       xdb.Filename,

  126                       ratIds.Count

  127                     );

  128 

  129                     // Even if only reading, commit the

  130                     // transaction (it's cheaper than aborting)

  131 

  132                     tr.Commit();

  133                   }

  134                 }

  135                 break;

  136               }

  137             }

  138           }

  139         }

  140       }

  141       catch (System.Exception ex)

  142       {

  143         ed.WriteMessage(

  144           "\nProblem reading/processing \"{0}\": {1}",

  145           pr.StringResult, ex.Message

  146         );

  147       }

  148     }

  149   }

  150 }

Here’s what happens when we run our updated command, selecting the same DWG as in the previous post (without the need to load it):

Command: XRA

Enter path to root drawing file: C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Civil\Master Site Plan.dwg

Drawing "C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Civil\Master Site Plan.dwg" ("C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Civil\Master Site Plan.dwg") with 18 RegAppIds

Drawing "PB-BASE" ("C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Civil\PB-BASE.dwg") with 7 RegAppIds

Drawing "PB-EX41" ("C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Civil\PB-EX41.dwg") with 6 RegAppIds

Drawing "PB-EX61" ("C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Civil\PB-EX61.dwg") with 5 RegAppIds

You’ll notice the “name” of the primary drawing is its full path: when we store this data in XML, we’ll go through the additional step of extracting the filename (System.IO.Path.GetFileNameWithoutExtension() makes this easy).

Counting the RegAppIds for the active AutoCAD drawing and its external references using .NET

Many of you will be aware of what has been referred to as the “RegAppId virus”: drawings that have been unfortunately polluted with excessive Registered Application IDs – which are used by applications to attach XData to entities – have these RegAppIds brought into a main drawing when Xrefed, duplicating and duplicating IDs that were often redundant in the first place. In fact – back in the day – I remember a very popular 3rd party application (which has long since been fixed and shall remain nameless) that erroneously used to create hundreds (if not thousands) of these IDs in each drawing it touched.

Back in AutoCAD 2005 (if I recall correctly) we extended the PURGE command to deal with RegAppIds, which was a partial solution to the problem. We also released a standalone RegAppId cleanup tool, which can help, too. Some developers have more specific requirements regarding RegAppId cleanup, especially when it comes to identifying the source of RegAppIds in a “polluted” drawing set.

This week we’re going to look at one potential way to help identify these problematic files. Part of the issue is that when working with many such drawings, some may be corrupted, etc. We also want to avoid having each drawing to be loaded in the AutoCAD editor, as that will cause the identification process to work more slowly.

We do, however, still want to use AutoCAD to execute this code, even on drawings that are not editor-resident: we don’t want to have to use RealDWG to build a tool.

I see the solution developing in steps that we’ll see in a number of (hopefully consecutive) blog posts:

1. Implement a command to collect RegAppId information for the active document
2. Extend this command to work on a drawing not loaded in the editor
3. Save our RegAppId information to some persistent location (XML?)
4. Create a modified version of ScriptPro 2.0 (one of our Plugins of the Month) to call our command without opening the drawing

Step 1 is addressed in today’s post – we’ll hopefully manage to complete the other steps in the following ones. I haven’t yet decided whether we should tackle the actual purge in this series of posts, or whether to keep it to identification, only. We’ll see how things go.

Here’s our initial command implementation in C#:

using Autodesk.AutoCAD.ApplicationServices;

using Autodesk.AutoCAD.DatabaseServices;

using Autodesk.AutoCAD.EditorInput;

using Autodesk.AutoCAD.Runtime;

using System.Collections.Generic;

using System.IO;

using System;

 

namespace XrefRegApps

{

  public class Commands

  {

    [CommandMethod("XRA")]

    public void ExternalReferenceRegisteredApps()

    {

      Document doc =

          Application.DocumentManager.MdiActiveDocument;

      Database db = doc.Database;

      Editor ed = doc.Editor;

 

      // Get the XrefGraph for the active document's database

 

      XrefGraph xg = db.GetHostDwgXrefGraph(true);

 

      // Loop through the nodes in the graph

 

      for (int i = 0; i < xg.NumNodes; i++)

      {

        // Get each node and check its status

 

        XrefGraphNode xgn = xg.GetXrefNode(i);

 

        switch (xgn.XrefStatus)

        {

          // If Un*, print a message

 

          case XrefStatus.Unresolved:

            ed.WriteMessage(

              "\nUnresolved xref \"{0}\"", xgn.Name

            );

            break;

          case XrefStatus.Unloaded:

            ed.WriteMessage(

              "\nUnloaded xref \"{0}\"", xgn.Name

            );

            break;

          case XrefStatus.Unreferenced:

            ed.WriteMessage(

              "\nUnreferenced xref \"{0}\"", xgn.Name

            );

            break;

          case XrefStatus.Resolved:

          {

            // If Resolved, get the RegAppTable

 

            Database xdb = xgn.Database;

            if (xdb != null)

            {

              Transaction tr =

                xdb.TransactionManager.StartTransaction();

              using (tr)

              {

                RegAppTable rat =

                  (RegAppTable)tr.GetObject(

                    xdb.RegAppTableId,

                    OpenMode.ForRead

                  );

 

                // Collect the contained RegAppTableRecord names

                // (i.e. the RegAppIds) in a list

 

                List<String> ratIds = new List<string>();

                foreach (ObjectId id in rat)

                {

                  RegAppTableRecord ratr =

                    (RegAppTableRecord)tr.GetObject(

                      id,

                      OpenMode.ForRead

                    );

                  ratIds.Add(ratr.Name);

                }

 

                // Print the drawing information

                // and the RegAppId count

 

                ed.WriteMessage(

                  "\nDrawing \"{0}\" (\"{1}\") with {2} RegAppIds",

                  xgn.Name,

                  xdb.Filename,

                  ratIds.Count

                );

 

                // Even if only reading, commit the transaction

                // (it's cheaper than aborting)

 

                tr.Commit();

              }

            }

            break;

          }

        }

      }

    }

  }

}

If we load the “Sample/Sheet Sets/Civil/Master Site Plan.dwg” file that ships with AutoCAD into the editor and run our XRA command, we should see the following output:

Command: XRA

Drawing "Master Site Plan" ("C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Civil\Master Site Plan.dwg") with 18 RegAppIds

Drawing "PB-BASE" ("C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Civil\PB-BASE.dwg") with 7 RegAppIds

Drawing "PB-EX41" ("C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Civil\PB-EX41.dwg") with 6 RegAppIds

Drawing "PB-EX61" ("C:\Program Files\Autodesk\AutoCAD 2011\Sample\Sheet Sets\Civil\PB-EX61.dwg") with 5 RegAppIds

If we want to find out the details of the specific RegAppIds – which we will eventually be writing to some kind of XML document, I expect – we can add a few lines of code after our existing WriteMessage() call:

ratIds.ForEach(

  delegate(string name) { ed.WriteMessage(" " + name); }

);

This will use WriteMessage() to print each RegAppId string – separated by spaces – to the command-line.

This is likely to be common issue that many of you will already have addressed in some way. Feel free to post a comment should you have any input. I have no doubt that other (and quite possibly better) solutions exist, but it seemed to me that this approach would be of more general interest to people wanting to perform some kind of batch processing operation without having to have drawings loaded in the AutoCAD editor.

Technology advances & the Managed Windows API

Yesterday my two sons – who are now 6 and 4, both great ages – managed to get me to sit (several times, of course) on a whoopee cushion. Which brought back many fond memories of my brother and I playing similar tricks at around that age. What amazed me most was how the technology has advanced: this latest generation of cushion self-inflates! A simple enough innovation – the rubber now contains a small hole and a sponge – but in many ways revolutionary. Ah, if only I had a time machine I could make a small (but very noisy) fortune. :-)

Anyway, enough about that. In today’s post I wanted to share a potentially useful resource that was brought to my attention by Augusto Gonçalves (thanks, Augusto! :-), the Managed Windows API.

Here are excerpts from this site regarding the problem…

If you want use Windows functionality in a .NET application which is not covered by the .NET framework (there is no "managed API" available for it), you usually have to use PInvoke, an interface that allows to invoke raw API functions from C# and VB.NET.

And the solution…

"Managed Windows API" is a collection of C# components that wrap Windows API functionality. It contains those features the author needed for his C# development, but if you have components yourself you want to share, please submit them so that this project can grow.

Before going any further I should state that I haven’t actually tried using this myself – and so cannot comment on its capabilities or quality – but the concept is promising and it’s available with full source code.

If you have any experience with this layer – or take the time to look into – please do post a comment.

Returning an average point to the AutoCAD command-line using .NET

This request came in over the weekend:

There is a useful object snap in AutoCAD for the mid point of 2 selected points. I would like a midpoint (average) of 3 (or more) points. Could this work in 3D as well as 2D?  It’s useful when drawing building surveys, often you triangulate a point from several and there are often ‘minimal’ differences in the dimension and you just take the average.

Given the fact we’re actually talking about an arbitrary number of points that will almost certainly not belong to a single entity, object snaps are probably neither the easiest nor the most appropriate way to solve this problem.

The below C# code registers a transparent command – AVG – which can be called from within drafting or modelling commands to calculate the average of a set of points (which can be selected using object snapping, should the user so wish). The resulting point is sent to the command-line – so the command really does need to be called transparently to be useful – which obviates the need for an object snap to be implemented.

using Autodesk.AutoCAD.ApplicationServices;

using Autodesk.AutoCAD.EditorInput;

using Autodesk.AutoCAD.Geometry;

using Autodesk.AutoCAD.Runtime;

using System.Collections.Generic;

using System.Linq;

using System;

 

namespace AveragePoint

{

  public class Commands

  {

    [CommandMethod("AVG", CommandFlags.Transparent)]

    public void AveragePoint()

    {

      Document doc =

          Application.DocumentManager.MdiActiveDocument;

      Editor ed = doc.Editor;

 

      // Prompt will be reused in our loop

 

      PromptPointOptions ppo =

        new PromptPointOptions("\nSelect point to average: ");

      ppo.AllowNone = true;

 

      // List of the points selected and our result object

 

      List<Point3d> pts = new List<Point3d>();

      PromptPointResult ppr;

 

      // The selection loop

 

      do

      {

        // If we have a valid point selection, add it to the list

 

        ppr = ed.GetPoint(ppo);

        if (ppr.Status == PromptStatus.OK)

          pts.Add(ppr.Value);

      }

      while (ppr.Status == PromptStatus.OK);

 

      // The loop will continue until a non-OK result...

      // We only care if Enter was used to terminate

 

      if (ppr.Status == PromptStatus.None)

      {

        // Create a string containing the point information:

        // the average of the selected coordinates

 

        string cmd =

          String.Format(

            "{0},{1},{2} ",

            pts.Average(a => a.X),

            pts.Average(a => a.Y),

            pts.Average(a => a.Z)

          );

 

        // Send it to the command-line

 

        doc.SendStringToExecute(cmd, true, false, true);

      }

    }

  }

}

Part of the beauty of this command (if I do say so myself ;-) is in its use of LINQ to average the list of points. It calculates the average X, Y and Z coordinates using a LINQ extension method on the List<> class, placing the results in a string that gets squirted into the command-line. We could just as easily have created a Point3d from these averages, of course, had that been the requirement.

Here’s how you’d use the command. Let’s start with some basic geometry:

Let’s now launch the LINE command, and then call AVG transparently. We’ll do so one with the end-points of the line, once with the corners of the triangle and finally with those of the rectangle. We can see we end up with  two lines connecting the mid-points of these shapes.

Here’s the command-line output, to see it at work:

Command: LINE

Specify first point: 'AVG

>>Select point to average:

>>Select point to average:

>>Select point to average:

Resuming LINE command.

Specify first point: 8.00080539552933,15.9545432099352,0

Specify next point or [Undo]: 'AVG

>>Select point to average:

>>Select point to average:

>>Select point to average:

>>Select point to average:

Resuming LINE command.

Specify next point or [Undo]: 15.9604077207532,14.8917902344987,0

Specify next point or [Undo]: 'AVG

>>Select point to average:

>>Select point to average:

>>Select point to average:

>>Select point to average:

>>Select point to average:

Resuming LINE command.

Specify next point or [Undo]: 26.731968038993,16.1501419209108,0

Specify next point or [Close/Undo]:

Command:

Here’s a quick test to see it working in 3D: the AVG was used to calculate the average of the peaks of three cones, returning the point for use as the start-point of a line:

As well as working in both 2D and 3D, the command appears to deal with custom user-coordinate systems without any trouble (as the average is made of the selected point – which is provided in UCS coordinates – before being sent to the command-line, which also expects UCS coordinates).

One outstanding concern I have – as it sends a point as a string to the command-line – is how it works in locales which use commas as the decimal point. I did some cursory testing, but if someone else could give it a spin and let me know how it works, that’d be great.

Although a very simple piece of code, this may well become a future Plugin of the Month: its simplicity actually makes it ideal as a project demonstrating the benefits of custom development.

A couple of streamlined solutions for AutoCAD using LINQ

I owe Chris Kratz a huge thanks for inspiring me to do more with LINQ. This post uses LINQ to provide more elegant solutions to a couple of problems described in previous posts.

The code in today’s post is probably my second brief foray into the world of LINQ. The comments Chris posted on the last post prompted me to spend a little time looking at LINQ over the weekend, and I really like it. I’d heard before that “LINQ is really just functional programming”, and in many ways I see that more clearly now, myself: the set of higher-order functions for manipulating data feel a lot like the capabilities provided in F#, for instance.

Here’s the C# code I put together:

using Autodesk.AutoCAD.ApplicationServices;

using Autodesk.AutoCAD.DatabaseServices;

using Autodesk.AutoCAD.EditorInput;

using Autodesk.AutoCAD.Geometry;

using Autodesk.AutoCAD.Runtime;

using System.Collections.Generic;

using System.Linq;

using System;

 

namespace PointSort

{

  public class Commands

  {

    public void PrintPoints(Editor ed, IEnumerable<Point3d> pts)

    {

      foreach (Point3d pt in pts)

      {

        ed.WriteMessage("{0}\n", pt);

      }

    }

 

    [CommandMethod("PTS")]

    public void PointSort()

    {

      Document doc =

          Application.DocumentManager.MdiActiveDocument;

      Editor ed = doc.Editor;

 

      // We'll use a random number generator

 

      Random rnd = new Random();

 

      // Generate the random set of points

 

      var pts =

        from n in Enumerable.Range(1, 20)

        select

          new Point3d(

            (2 * rnd.NextDouble() - 1) * 1000,

            (2 * rnd.NextDouble() - 1) * 1000,

            (2 * rnd.NextDouble() - 1) * 1000

          );

 

      // Order them by X then Y then Z

 

      var sorted =

        from Point3d pt in pts

        orderby pt.X, pt.Y, pt.Z

        select pt;

 

      ed.WriteMessage("\nPoints before sort:\n\n");

      PrintPoints(ed, pts);

      ed.WriteMessage("\n\nPoints after sort:\n\n");

      PrintPoints(ed, sorted);

    }

 

    [CommandMethod("CG")]

    public void CompleteGraph()

    {

      Document doc =

          Application.DocumentManager.MdiActiveDocument;

      Database db = doc.Database;

      Editor ed = doc.Editor;

 

      // Generate points, put them in a list

 

      double alpha = Math.PI * 2 / 19;

      var pts =

        (from n in Enumerable.Range(0, 19)

          select new Point3d(

            Math.Cos(n * alpha) * 5, Math.Sin(n * alpha) * 5, 0

          )

        ).ToList();

 

      // Generate lines from points

 

      var lns =

        from Point3d a in pts

        from Point3d b in pts

        where pts.IndexOf(b) > pts.IndexOf(a)

        select new Line(a, b);

 

      // Add them to the current space in the active drawing

 

      Transaction tr = db.TransactionManager.StartTransaction();

      using (tr)

      {

        BlockTableRecord btr =

          (BlockTableRecord)tr.GetObject(

            db.CurrentSpaceId,

            OpenMode.ForWrite

          );

        foreach (Line ln in lns)

        {

          btr.AppendEntity(ln);

          tr.AddNewlyCreatedDBObject(ln, true);

        }

        tr.Commit();

      }

    }

  }

}

The above code actually solves a couple of problems from previous posts.

Let’s start by looking at the PTS command:

• This now generates the random points directly, without the need for a set of helper functions
• The sort is now really easy, and (for the sake of it) has been modified to sort on X, then Y, then Z
• The code is shorter, also, as I’ve removed the Point2d solution

I decided to go back to this previous post and rework that, also, resulting in the CG command:

• This code generates a Complete Graph in AutoCAD (much more succinctly than before)
• One statement generates the points, one generates the lines between them
• The point generation does so with a redundant range enumeration (which we replace with points, without using the original enumeration)
• Someone may have a better (meaning more elegant – efficiency isn’t likely to be a major concern) way to do this, but this way does work

I won’t show the results again: they are as before in the respective, original posts.

In the next post we’ll use LINQ once more, this time to provide a solution to a request for a future Plugin of the Month (and this may prove to be the most succinct plugin published, to date, but we’ll see).

Sorting an AutoCAD Point2dCollection or Point3dCollection using .NET

Thanks to Virupaksha Aithal, from DevTech India, for providing the technical response to an ADN member than inspired this post.

When working with the Point2d and Point3d objects from AutoCAD’s .NET API it’s common to use the in-built collection types, Point2dCollection and Point3dCollection. Neither of these objects provides the capability to sort their contents (and, in any case, sorting would mean different things to different people when it comes to containers of objects with multiple data entries).

So how can you sort one of these collections?

The answer is fairly straightforward: you convert them to a .NET array, sort them using standard .NET capabilities and then recreate an AutoCAD collection.

The below C# code does this for collections of both Point2d and Point3d objects.

using Autodesk.AutoCAD.ApplicationServices;

using Autodesk.AutoCAD.EditorInput;

using Autodesk.AutoCAD.Geometry;

using Autodesk.AutoCAD.Runtime;

using System.Collections.Generic;

using System;

 

namespace PointSort

{

  internal class sort2dByX : IComparer<Point2d>

  {

    public static bool IsZero(double a)

    {

      return Math.Abs(a) < Tolerance.Global.EqualPoint;

    }

 

    public static bool IsEqual(double a, double b)

    {

      return IsZero(b - a);

    }

 

    public int Compare(Point2d a, Point2d b)

    {

      if (IsEqual(a.X, b.X)) return 0; // ==

      if (a.X < b.X) return -1; // <

      return 1; // >

    }

  }

 

  internal class sort3dByX : IComparer<Point3d>

  {

    public static bool IsZero(double a)

    {

      return Math.Abs(a) < Tolerance.Global.EqualPoint;

    }

 

    public static bool IsEqual(double a, double b)

    {

      return IsZero(b - a);

    }

 

    public int Compare(Point3d a, Point3d b)

    {

      if (IsEqual(a.X, b.X)) return 0; // ==

      if (a.X < b.X) return -1; // <

      return 1; // >

    }

  }

 

  public class Commands

  {

    private double DeNormalize(double a, double max)

    {

      // Random numbers are from 0 to 1.0, so we

      // multiply it out to be within our range

      // (this will create a value from -max to max)

 

      return (2 * a - 1) * max;

    }

 

    public Point2d Random2dPoint(Random rnd, double max)

    {

      double x = rnd.NextDouble(),

            y = rnd.NextDouble();

 

      return new Point2d(

        DeNormalize(x, max),

        DeNormalize(y, max)

      );

    }

 

    public Point3d Random3dPoint(Random rnd, double max)

    {

      double x = rnd.NextDouble(),

            y = rnd.NextDouble(),

            z = rnd.NextDouble();

 

      return new Point3d(

        DeNormalize(x, max),

        DeNormalize(y, max),

        DeNormalize(z, max)

      );

    }

 

    public Point2dCollection Random2dPoints(int num, double max)

    {

      Point2dCollection pts = new Point2dCollection(num);

      Random rnd = new Random();

      for (int i = 0; i < num; i++)

      {

        pts.Add(Random2dPoint(rnd, max));

      }

      return pts;

    }

 

    public Point3dCollection Random3dPoints(int num, double max)

    {

      Point3dCollection pts = new Point3dCollection();

      Random rnd = new Random();

      for (int i = 0; i < num; i++)

      {

        pts.Add(Random3dPoint(rnd, max));

      }

      return pts;

    }

 

    public void PrintPoints(Editor ed, Point2dCollection pts)

    {

      foreach (Point2d pt in pts)

      {

        ed.WriteMessage("{0}\n", pt);

      }

    }

 

    public void PrintPoints(Editor ed, Point3dCollection pts)

    {

      foreach (Point3d pt in pts)

      {

        ed.WriteMessage("{0}\n", pt);

      }

    }

 

    [CommandMethod("PTS")]

    public void PointSort()

    {

      Document doc =

          Application.DocumentManager.MdiActiveDocument;

      Editor ed = doc.Editor;

 

      Point2dCollection pts2d = Random2dPoints(20, 1000.0);

      Point2d[] raw = pts2d.ToArray();

      Array.Sort(raw, new sort2dByX());

      Point2dCollection sorted2d = new Point2dCollection(raw);

 

      ed.WriteMessage("\n2D points before sort:\n\n");

      PrintPoints(ed, pts2d);

      ed.WriteMessage("\n\n2D points after sort:\n\n");

      PrintPoints(ed, sorted2d);

 

      Point3dCollection pts3d = Random3dPoints(20, 1000.0);

      Point3d[] raw3d = new Point3d[pts3d.Count];

      pts3d.CopyTo(raw3d, 0);

      Array.Sort(raw3d, new sort3dByX());

      Point3dCollection sorted3d = new Point3dCollection(raw3d);

 

      ed.WriteMessage("\n3D points before sort:\n\n");

      PrintPoints(ed, pts3d);

      ed.WriteMessage("\n\n3D points after sort:\n\n");

      PrintPoints(ed, sorted3d);

    }

  }

}

Some notes on this implementation:

• For the purposes of this example, we’re assuming “sorting” means to sort on the X value of each point
  • It should be obvious how to change the implementation to use different sort criteria
• To test the sorting, we’re populating the collections with a set of randomly-generated points
  • We create 20 points in each collection, each with coordinates in the range of –1000 to 1000
  • I’ve kept the number of points in each collection low, just to keep the post to a reasonable length and still be able to include the results
• Converting to a .NET array is a little different for 2D and 3D collections
  • Point2dCollection has the ToArray() method
  • Point3dCollection has the CopyTo() method

Something I will say about the above code... It’s code like this that makes me yearn for a more dynamic environment (I’m writing this in “classic”, statically-typed C#). There are several duplicate classes with basically the same implementation but taking different types: plenty of code that just feels redundant.

It would be interesting to rework this IronPython, to see what that it brings (or even to see if using the dynamic keyword would help – I should really install VS 2010 and give it a try). This is also exactly the kind of problem that F# excels at solving, so I’ll expect I’ll be giving that a try, too, before too long, just to see how much code can be ripped out.

Here are some sample results from  running the PTS command:

Command: PTS 

2D points before sort:

 

(546.62044884014,333.683370302284)

(273.865409788613,671.008432130799)

(786.237089795171,-664.37283328938)

(-951.588503062533,-221.942868652727)

(-362.490728200642,-93.6347987007512)

(-938.590817124858,-889.46122764119)

(628.55356355596,-180.880018128492)

(485.986099339084,329.109809980313)

(525.820961001246,-659.813289372164)

(-902.095012321181,-931.107034874664)

(683.452251219867,931.710177069395)

(110.748492698534,-899.346025613763)

(47.6774876227963,-794.155224130561)

(-993.500254113926,438.08932389975)

(994.927220044158,-722.431948279232)

(198.020555636855,462.94129894252)

(-693.78015850381,-930.635690656787)

(-330.415913523369,497.267734025264)

(-855.102567866027,951.917634323201)

(520.609316192851,-779.07530860001)

 

 

2D points after sort:

 

(-993.500254113926,438.08932389975)

(-951.588503062533,-221.942868652727)

(-938.590817124858,-889.46122764119)

(-902.095012321181,-931.107034874664)

(-855.102567866027,951.917634323201)

(-693.78015850381,-930.635690656787)

(-362.490728200642,-93.6347987007512)

(-330.415913523369,497.267734025264)

(47.6774876227963,-794.155224130561)

(110.748492698534,-899.346025613763)

(198.020555636855,462.94129894252)

(273.865409788613,671.008432130799)

(485.986099339084,329.109809980313)

(520.609316192851,-779.07530860001)

(525.820961001246,-659.813289372164)

(546.62044884014,333.683370302284)

(628.55356355596,-180.880018128492)

(683.452251219867,931.710177069395)

(786.237089795171,-664.37283328938)

(994.927220044158,-722.431948279232)

 

3D points before sort:

 

(-282.271111981138,909.546242053409,285.631638618946)

(371.393521023632,762.584686168742,-119.380790330181)

(386.957248387373,-908.643945077734,648.815548815213)

(494.069362754966,93.28737999,323.425575775758)

(494.450510244095,586.600064107496,680.753123797827)

(489.99652056489,712.608007580325,660.061542717768)

(132.996848380657,-910.9989078301,-602.627639473708)

(564.335921576403,-454.319581135325,78.9875290724391)

(276.740193961533,837.884722202031,922.783010603293)

(-314.830172487921,370.544476141475,-925.548076594969)

(865.08049995875,-543.389787684842,101.277599624022)

(-267.499718473991,616.808070622761,558.13882665622)

(-782.131620581323,-289.302226756374,373.464381961834)

(832.297310155024,-629.765324122163,523.183570021383)

(614.174030541523,-112.834495079161,366.034026893803)

(-234.866094419205,43.4879246370345,265.665525228561)

(-255.009830582426,195.9628114458,-851.765022544081)

(374.128198891007,532.42736753655,-900.2289231402)

(-385.354406845455,153.392966442459,363.865823188734)

(-793.355890453493,-905.346672937901,924.69996396671)

 

 

3D points after sort:

 

(-793.355890453493,-905.346672937901,924.69996396671)

(-782.131620581323,-289.302226756374,373.464381961834)

(-385.354406845455,153.392966442459,363.865823188734)

(-314.830172487921,370.544476141475,-925.548076594969)

(-282.271111981138,909.546242053409,285.631638618946)

(-267.499718473991,616.808070622761,558.13882665622)

(-255.009830582426,195.9628114458,-851.765022544081)

(-234.866094419205,43.4879246370345,265.665525228561)

(132.996848380657,-910.9989078301,-602.627639473708)

(276.740193961533,837.884722202031,922.783010603293)

(371.393521023632,762.584686168742,-119.380790330181)

(374.128198891007,532.42736753655,-900.2289231402)

(386.957248387373,-908.643945077734,648.815548815213)

(489.99652056489,712.608007580325,660.061542717768)

(494.069362754966,93.28737999,323.425575775758)

(494.450510244095,586.600064107496,680.753123797827)

(564.335921576403,-454.319581135325,78.9875290724391)

(614.174030541523,-112.834495079161,366.034026893803)

(832.297310155024,-629.765324122163,523.183570021383)

(865.08049995875,-543.389787684842,101.277599624022)

Update

Thanks to Dan Smith for provide a refactored version of the code: if you use multiple inheritance – in the case of our “comparer” classes – and generics/LINQ – in the case of the point generation piece – then it’s certainly possible to factor out the redundant code in good old C#. (You will have to target .NET Framework 3.5 or higher to get this to build.)

using Autodesk.AutoCAD.ApplicationServices;

using Autodesk.AutoCAD.EditorInput;

using Autodesk.AutoCAD.Geometry;

using Autodesk.AutoCAD.Runtime;

using System.Collections.Generic;

using System.Linq;

using System;

 

namespace PointSort

{

  internal class sortByX

  {

    protected static bool IsZero(double a)

    {

      return Math.Abs(a) < Tolerance.Global.EqualPoint;

    }

 

    protected static bool IsEqual(double a, double b)

    {

      return IsZero(b - a);

    }

 

    protected int Compare(double aX, double bX)

    {

      if (IsEqual(aX, bX)) return 0; // ==

      if (aX < bX) return -1; // <

      return 1; // >

    }

  }

 

  internal class sort2dByX : sortByX, IComparer<Point2d>

  {

    public int Compare(Point2d a, Point2d b)

    {

      return base.Compare(a.X, b.X);

    }

  }

 

  internal class sort3dByX : sortByX, IComparer<Point3d>

  {

    public int Compare(Point3d a, Point3d b)

    {

      return base.Compare(a.X, b.X);

    }

  }

 

  public class Commands

  {

    private double DeNormalize(double a, double max)

    {

      // Random numbers are from 0 to 1.0, so we

      // multiply it out to be within our range

      // (this will create a value from -max to max)

 

      return (2 * a - 1) * max;

    }

 

    public Point2d Random2dPoint(Random rnd, double max)

    {

      double x = rnd.NextDouble(),

            y = rnd.NextDouble();

 

      return new Point2d(

        DeNormalize(x, max),

        DeNormalize(y, max)

      );

    }

 

    public Point3d Random3dPoint(Random rnd, double max)

    {

      double x = rnd.NextDouble(),

            y = rnd.NextDouble(),

            z = rnd.NextDouble();

 

      return new Point3d(

        DeNormalize(x, max),

        DeNormalize(y, max),

        DeNormalize(z, max)

      );

    }

 

    TPoint[] RandomPoints<TPoint>(

      int num, double max, Func<Random, double, TPoint> generator

    )

    {

      var pts = new TPoint[num];

      var rnd = new Random();

 

      for (int i = 0; i < num; i++)

      {

        pts[i] = generator(rnd, max);

      }

      return pts;

    }

 

    public Point2dCollection Random2dPoints(int num, double max)

    {

      var pts = RandomPoints<Point2d>(num, max, Random2dPoint);

      return new Point2dCollection(pts);

    }

 

    public Point3dCollection Random3dPoints(int num, double max)

    {

      var pts = RandomPoints<Point3d>(num, max, Random3dPoint);

      return new Point3dCollection(pts);

    }

 

    public void PrintPoints(Editor ed, Point2dCollection pts)

    {

      foreach (Point2d pt in pts)

      {

        ed.WriteMessage("{0}\n", pt);

      }

    }

 

    public void PrintPoints(Editor ed, Point3dCollection pts)

    {

      foreach (Point3d pt in pts)

      {

        ed.WriteMessage("{0}\n", pt);

      }

    }

 

    [CommandMethod("PTS")]

    public void PointSort()

    {

      Document doc =

          Application.DocumentManager.MdiActiveDocument;

      Editor ed = doc.Editor;

 

      Point2dCollection pts2d = Random2dPoints(20, 1000.0);

      Point2d[] raw = pts2d.ToArray();

      Array.Sort(raw, new sort2dByX());

      Point2dCollection sorted2d = new Point2dCollection(raw);

 

      ed.WriteMessage("\n2D points before sort:\n\n");

      PrintPoints(ed, pts2d);

      ed.WriteMessage("\n\n2D points after sort:\n\n");

      PrintPoints(ed, sorted2d);

 

      Point3dCollection pts3d = Random3dPoints(20, 1000.0);

      Point3d[] raw3d = new Point3d[pts3d.Count];

      pts3d.CopyTo(raw3d, 0);

      Array.Sort(raw3d, new sort3dByX());

      Point3dCollection sorted3d = new Point3dCollection(raw3d);

 

      ed.WriteMessage("\n3D points before sort:\n\n");

      PrintPoints(ed, pts3d);

      ed.WriteMessage("\n\n3D points after sort:\n\n");

      PrintPoints(ed, sorted3d);

    }

  }

}

It’s still more verbose than I’d like, given the relatively low complexity of the problem, so I’ll still give IronPython and F# a go to see how they compare, when I get the chance.

Checking your application has enough memory for an operation using .NET

From time to time I listen to the .NET Rocks show – I don’t get the chance to listen every week, but I do browse through the RSS items I get for the show episodes and find some time to put those I find of particular interest on in the background while I’m working on something else.

Yesterday’s episode caught my eye, as it focused on the nKinect project, exposing the Kinect’s capabilities to .NET. And ’m really (and I mean really) excited about the Xbox Kinect. I mentioned it in passing in a post from last March (it was still called Project Natal, back then) and it’s pretty clear to me that this device – and those like it – are set to change the industry. I’ve had a Kinect on order since the beginning of December (frustratingly you can’t get the Xbox 360 S 250Gb Kinect bundle, here, for love nor money), but in the meantime I’m having to be content with seeing what other people are managing to do with them. In particular the work of Oliver Kreylos is really worth checking out. There there's all the fun stuff on Kinect Hacks... from the ability to control applications, Minority Report-style to the potentially even more useful ability to transform yourself into a Japanese Super-Hero. :-)

While it’s the nKinect interview – which turned out to be a little disappointing due to its slight lack of fluidity – that caused me to listen to the episode, there was one piece of information earlier in the show that really got my attention: in the regular “Better Know a Framework” segment, Carl Franklin mentioned System.Runtime.MemoryFailPoint, a .NET Framework class that can be used to check for available memory prior to calling a memory-consuming operation.

I decided to give it a go, wrapping it into a helper function to simplify the memory check.

Here’s the C# code:

using Autodesk.AutoCAD.ApplicationServices;

using Autodesk.AutoCAD.EditorInput;

using Autodesk.AutoCAD.Runtime;

using System.Runtime;

using System;

 

namespace MemoryHog

{

  public class MemoryConsumingApp

  {

    // Helper function to check for adequate memory

 

    bool CanGetMemory(int megabytes)

    {

      try

      {

        MemoryFailPoint mfp = new MemoryFailPoint(megabytes);

      }

      catch (InsufficientMemoryException)

      {

        return false;

      }

      return true;

    }

 

    [CommandMethod("MEM")]

    public void CheckForMemoryBeforeRunning()

    {

      Document doc =

          Application.DocumentManager.MdiActiveDocument;

      Editor ed = doc.Editor;

 

      // Ask for the amount of memory for which to check

 

      PromptIntegerOptions pio =

        new PromptIntegerOptions(

          "\nEnter amount of memory (in megabytes) to check for: "

        );

      pio.AllowNegative = false;

      pio.AllowNone = false;

      pio.AllowZero = false;

 

      PromptIntegerResult pir = ed.GetInteger(pio);

 

      // Check for the memory

 

      bool canProceed = CanGetMemory(pir.Value);

 

      ed.WriteMessage(

        "\n{0}ufficient memory to complete operation.",

        canProceed ? "S" : "Ins"

      );

 

      if (!canProceed) return;

 

      // Perform operation

      // ...

    }

  }

}

I ended up adding some code to prompt the user for the amount of memory (in megabytes) for which to check, mainly as it gives the chance to vary the amount and is therefore more interesting to play around with. In your applications you’ll have the interesting job of calculating the amount of memory a particular task will require.

I structured the code at the end of the command to show the kind of logic I would use to test for sufficient memory and then return from the command, should it not be available.

Here’s some fun I had using this MEM command to determine how much memory is available to my application during an AutoCAD session with various other applications running on my 32-bit Vista system:

 

Command: MEM

Enter amount of memory (in megabytes) to check for: 50

Sufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 100

Sufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 150

Sufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 300

Insufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 200

Sufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 250

Sufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 280

Sufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 290

Sufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 295

Insufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 298

Sufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 299

Sufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 300

Sufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 301

Sufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 310

Sufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 320

Sufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 330

Sufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 340

Sufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 360

Sufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 380

Sufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 400

Sufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 500

Insufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 450

Sufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 470

Sufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 480

Sufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 490

Insufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 485

Insufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 483

Insufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 482

Insufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 481

Insufficient memory to complete operation.

Command:  MEM

Enter amount of memory (in megabytes) to check for: 480

Sufficient memory to complete operation.

I tried to zero in on the amount of memory available, but as you can see (and as is logical), this amount fluctuates according to (or inversely to, I suppose) memory usage. I started zeroing in on a number at around 300Mb, but the number I eventually ended up with was 480Mb (and this was after a session where the application only had around 70Mb available to it).

This really isn’t intended as an interactive tool to determine what memory is available, but I thought I’d just mention these results as an aside.

Combining AutoCAD blocks in separate files into a single DWG using .NET – Take 2

Thanks for Chris, Dan and Dale for pointing out the obvious issue(s) with my last post. Let’s just blame it on a few holiday cobwebs needing brushing away during the first week back in the saddle. :-)

The main issue with my previous implementation was that I’d somehow forgotten that Database.Insert() allows you to insert into a named block definition. This simple function does all my previous, manual approach did and more.

The secondary issue – but still very important to those using annotation scaling – is that the previous code does not work for annotative blocks, as Dan very rightly pointed out. I’ve incorporated Dan’s approach into today’s post to make it more complete.

I’ve decided to leave the original post as it is – as the technique is somewhat interesting at a certain level – even if today’s post supercedes it.

Here’s the updated C# code:

using Autodesk.AutoCAD.ApplicationServices;

using Autodesk.AutoCAD.DatabaseServices;

using Autodesk.AutoCAD.EditorInput;

using Autodesk.AutoCAD.Runtime;

using System.IO;

using System;

 

namespace BlockImport

{

  public class BlockImportClass

  {

    [CommandMethod("CBL")]

    public void CombineBlocksIntoLibrary()

    {

      Document doc =

          Application.DocumentManager.MdiActiveDocument;

      Editor ed = doc.Editor;

      Database destDb = doc.Database;

 

      // Get name of folder from which to load and import blocks

 

      PromptResult pr =

        ed.GetString("\nEnter the folder of source drawings: ");

 

      if (pr.Status != PromptStatus.OK)

        return;

      string pathName = pr.StringResult;

 

      // Check the folder exists

 

      if (!Directory.Exists(pathName))

      {

        ed.WriteMessage(

          "\nDirectory does not exist: {0}", pathName

        );

        return;

      }

 

      // Get the names of our DWG files in that folder

 

      string[] fileNames = Directory.GetFiles(pathName, "*.dwg");

 

      // A counter for the files we've imported

 

      int imported = 0, failed = 0;

 

      // For each file in our list

 

      foreach (string fileName in fileNames)

      {

        // Double-check we have a DWG file (probably unnecessary)

 

        if (fileName.EndsWith(

              ".dwg",

              StringComparison.InvariantCultureIgnoreCase

            )

        )

        {

          // Catch exceptions at the file level to allow skipping

 

          try

          {

            // Suggestion from Thorsten Meinecke...

 

            string destName =

              SymbolUtilityServices.GetSymbolNameFromPathName(

                fileName, "dwg"

              );

 

            // And from Dan Glassman...

 

            destName =

              SymbolUtilityServices.RepairSymbolName(

                destName, false

              );

 

            // Create a source database to load the DWG into

 

            using (Database db = new Database(false, true))

            {

              // Read the DWG into our side database

 

              db.ReadDwgFile(fileName, FileShare.Read, true, "");

              bool isAnno = db.AnnotativeDwg;

 

              // Insert it into the destination database as

              // a named block definition

 

              ObjectId btrId = destDb.Insert(

                destName,

                db,

                false

              );

 

              if (isAnno)

              {

                // If an annotative block, open the resultant BTR

                // and set its annotative definition status

 

                Transaction tr =

                  destDb.TransactionManager.StartTransaction();

                using (tr)

                {

                  BlockTableRecord btr =

                    (BlockTableRecord)tr.GetObject(

                      btrId,

                      OpenMode.ForWrite

                    );

                  btr.Annotative = AnnotativeStates.True;

                  tr.Commit();

                }

              }

 

              // Print message and increment imported block counter

 

              ed.WriteMessage("\nImported from \"{0}\".", fileName);

              imported++;

            }

          }

          catch (System.Exception ex)

          {

            ed.WriteMessage(

              "\nProblem importing \"{0}\": {1} - file skipped.",

              fileName, ex.Message

            );

            failed++;

          }

        }

      }

 

      ed.WriteMessage(

        "\nImported block definitions from {0} files{1} in " +

        "\"{2}\" into the current drawing.",

        imported,

        failed > 0 ? " (" + failed + " failed)" : "",

        pathName

      );

    }

  }

}

The results are just as we saw with the previous code, so I won’t repeat them.

Update

I made a small update to the code, to make use of SymbolUtilityServices.GetSymbolNameFromPathName() rather than Path.GetFileNameWithoutExtension(). Thanks to Thorsten Meinecke for making this suggestion.

Update 2

Followed by a minor code update to fix simplify the post-edit of annotative block definitions as well as an additional call to SymbolUtilityServices.RepairSymbolName() recommended by Dan Glassman (thanks, Dan! :-).