Displaying a progress meter during long operations in AutoCAD using .NET

It's often desirable to show a progress meter during lengthy operations. Although there's currently no public API to make use of AutoCAD's progress meter from .NET, there are nevertheless a couple of approaches to doing so.

In this post I'll show how to do this using P/Invoke (using some code borrowed from Fenton Webb, from DevTech Americas) and in my next post I'll show how to use the "internal" AutoCAD managed assembly.

Here's the C# code that uses P/Invoke, which should work for AutoCAD 2007 and 2008:

using Autodesk.AutoCAD.Runtime;

using System.Runtime.InteropServices;

using System.Windows.Forms;

namespace ProgressMeterTest

{

  public class Cmds

  {

    [DllImport(

      "acad.exe",

      CharSet = CharSet.Auto,

      CallingConvention = CallingConvention.Cdecl,

      EntryPoint = "?acedSetStatusBarProgressMeter@@YAHPB_WHH@Z"

      //This should work for AutoCAD 2006...

      //EntryPoint = "?acedSetStatusBarProgressMeter@@YAHPBDHH@Z"

  )]

    private static extern int

      acedSetStatusBarProgressMeter(

        string label,

        int minPos,

        int maxPos

      );

    [DllImport(

      "acad.exe",

      CharSet = CharSet.Auto,

      CallingConvention = CallingConvention.Cdecl,

      EntryPoint = "?acedSetStatusBarProgressMeterPos@@YAHH@Z"

    )]

    private static extern int

      acedSetStatusBarProgressMeterPos(int pos);

    [DllImport(

      "acad.exe",

      CharSet = CharSet.Auto,

      CallingConvention = CallingConvention.Cdecl,

      EntryPoint = "?acedRestoreStatusBar@@YAXXZ"

    )]

    private static extern int acedRestoreStatusBar();

    [CommandMethod("PB")]

    public void ProgressBar()

    {

      acedSetStatusBarProgressMeter("Testing Progress Bar", 0, 100);

      for (int i = 0; i <= 100; i++)

      {

        for (int j = 0; j <= 10; j++)

        {

          System.Threading.Thread.Sleep(1);

          acedSetStatusBarProgressMeterPos(i);

          // This allows AutoCAD to repaint

          Application.DoEvents();

        }

      }

      acedRestoreStatusBar();

    }

  }

}

And here's what you see when it runs:

Update:

Thanks to Chris Bray for pointing out the above technique (and the one I was about to show in Part 2) is unnecessary from AutoCAD 2007 onwards. A new class was introduced in AutoCAD 2007 called Autodesk.AutoCAD.Runtime.ProgressMeter.

Here's some C# code that demonstrates the use of this class:

using Autodesk.AutoCAD.Runtime;

using System.Runtime.InteropServices;

using System.Windows.Forms;

namespace ProgressMeterTest

{

  public class Cmds

  {

    [CommandMethod("PB")]

    public void ProgressBarManaged()

    {

      ProgressMeter pm = new ProgressMeter();

      pm.Start("Testing Progress Bar");

      pm.SetLimit(100);

      // Now our lengthy operation

      for (int i = 0; i <= 100; i++)

      {

        System.Threading.Thread.Sleep(5);

        // Increment Progress Meter...

        pm.MeterProgress();

        // This allows AutoCAD to repaint

        Application.DoEvents();

      }

      pm.Stop();

    }

  }

}

The original code is still the technique to use for AutoCAD 2005 & 2006, although you will need to uncomment the line in the DllImport attribute for acedSetStatusBarProgressMeter(), to make sure it uses the EntryPoint with the non-Unicode string argument ("?acedSetStatusBarProgressMeter@@YAHPBDHH@Z"). You'll clearly also need to comment out the current EntryPoint assignment, of course.

I'll forego the Part 2 post (and rename this one from Part 1), as there's really no need to look any other technique for this, at this stage.