An object of the WPF.
public class TextControlDocument : System.Windows.Controls.Canvas
Public Class TextControlDocument
Inherits System.Windows.Controls.Canvas
Introduced: X12.
To obtain the Text
TXTextControl.WPF.TextControlDocument document =
textControl1.Template.FindName("TXPART_Document", textControl1) as TXTextControl.WPF.TextControlDocument;
Dim document As TXTextControl.WPF.TextControlDocument =
TryCast(textControl1.Template.FindName("TXPART_Document", textControl1), TXTextControl.WPF.TextControlDocument)