Deleting xdata

By Xiaodong Liang

Issue
How do I delete Xdata that is attached to an entity?

Solution
The following sample code demonstrates how to delete an Entity's Extended Entity data.

VBA:

Sub test()
   Dim obj As Object
   Dim xtype(0) As Integer
   Dim xvalue(0) As Variant
   xtype(0) = 1001
   'MyApp is assumed to be the registered application.
   xvalue(0) = "MyApp"
   'select an entity
   ThisDrawing.Utility.GetEntity obj, pt, "Pick: "
   ' remove the xdata
   obj.SetXData xtype, xvalue
End Sub

C#:

[CommandMethod("REMXDATA")]
static public void RemoveXdata() 
{
    Document doc = 
        Autodesk.AutoCAD.ApplicationServices.Application.
        DocumentManager.MdiActiveDocument;
    Database db = doc.Database;
    Transaction tr = 
        db.TransactionManager.StartTransaction();
 
    using (tr)
    {
        Editor ed =             Application.DocumentManager.MdiActiveDocument.Editor; 
        try
        {
            // Prompt the user to select an entity
            PromptEntityResult ers;
            ers = ed.GetEntity("Pick entity ");
            // Open the selected entity
            Entity ent = 
                (Entity)tr.GetObject(ers.ObjectId,
                OpenMode.ForWrite);
            // This call would ensure that the Xdata of the entity
            // associated with ADSK application name only would be removed
            ent.XData = new ResultBuffer(
                new TypedValue(1001, "ADSK"));
            tr.Commit();
        }
        catch (System.Exception ex)
        {
       ed.WriteMessage("Exception while removing Xdata: "
                + ex.Message);
            tr.Abort();
        }
        finally
        {
        }
    }
}