Changing the case of an MText object using AutoCADs in-place editor from .NET

June 18, 2010

Changing the case of an MText object using AutoCAD’s in-place editor from .NET

In the last post we saw a very simple, preliminary exploration of some of the new programmatic capabilities of the in-place MText editor in AutoCAD 2011. In that basic case we just used it to strip off all formatting from an MText object. Now we’re going to implement a couple of commands to toggle the case of the contents of an MText object between lower- and uppercase.

Here’s the C# code:

using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.EditorInput;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.Runtime;
 
namespace MTextEditing
{
  public class Commands
  {
    [CommandMethod("CTU")]
    public void ChangeToUppercase()
    {
      ChangeCase(true);
    }
 
    [CommandMethod("CTL")]
    public void ChangeToLowercase()
    {
      ChangeCase(false);
    }
 
    private void ChangeCase(bool upper)
    {
      Document doc =
        Application.DocumentManager.MdiActiveDocument;
      Database db = doc.Database;
      Editor ed = doc.Editor;
 
      // Specifically select an MText object
 
      PromptEntityOptions peo =
        new PromptEntityOptions(
          string.Format(
            "\nSelect MText to change to {0}case: ",
            upper ? "upper" : "lower"
          )
        );
      peo.SetRejectMessage("\nObject must be MText.");
      peo.AddAllowedClass(typeof(MText), false);
 
      PromptEntityResult per = ed.GetEntity(peo);
      if (per.Status != PromptStatus.OK)
        return;
 
      Transaction tr =
        doc.TransactionManager.StartTransaction();
      using (tr)
      {
        // We only need our MText open for read
 
        DBObject obj =
          tr.GetObject(per.ObjectId, OpenMode.ForRead, false);
        MText mt = obj as MText;
 
        if (mt == null)
          return;
 
        // Create a text editor object for the MText
 
        TextEditor te = TextEditor.CreateTextEditor(mt);
        if (te == null)
          return;
 
        // Select the entire contents of the MText
 
        te.SelectAll();
        TextEditorSelection sel = te.Selection;
        if (sel == null)
          return;
 
        // Check whether we can change the selection's
        // case, and then do so
 
        if (sel.CanChangeCase)
        {
          if (upper)
            sel.ChangeToUppercase();
          else
            sel.ChangeToLowercase();
        }
 
        // Be sure to save the results from the editor
 
        te.Close(TextEditor.ExitStatus.ExitSave);
        tr.Commit();
      }
    }
  }
}

After building the code into a DLL and NETLOADing it, we can use our new custom commands to change the case of the entire contents of an MText object.

Before…