Starts a new undo operation.
Assembly: EnvDTE (in EnvDTE.dll)
If the UndoContext object is already open when the method is performed, it produces an error.
If undo stack linkage is strict, all the linked undo sibling stacks must be undone together or not at all. A strict linked undo operation is usually necessary for simultaneous text changes across multiple files, such as a header file and a Visual C++ file. This is, in fact, the model used in Visual Studio. For more information about undo stack linking, see the OpenLinkedUndo method.
Sub OpenExample() ' Before running, select text in an open document. Dim txtSel As TextSelection Dim strTS As String, boolWasOpen As Boolean txtSel = DTE.ActiveDocument.Selection strTS = txtSel.Text ' Check to see if UndoContext object is already open. If DTE.UndoContext.IsOpen = True Then boolWasOpen = True Else ' Open the UndoContext object to track changes. DTE.UndoContext.Open("RemoveNewLines", False) End If ' Perform search for newline characters and remove them. If strTS <> "" Then txtSel.Delete() strTS = Replace(strTS, vbNewLine, "", Compare:=vbTextCompare) txtSel.Insert(strTS) End If ' If UndoContext was already open, don't close it. If boolWasOpen = False Then ' Close the UndoContext object to commit the changes. DTE.UndoContext.Close() End If End Sub
- Full trust for the immediate caller. This member cannot be used by partially trusted code. For more information, see Using Libraries from Partially Trusted Code.