CRichEditCtx.Undomethod

This message undoes the last edit control operation in the control's undo queue.

Syntax

FUNCTION Undo () AS LONG

FUNCTION Undo (BYVAL Count AS LONG) AS LONG

Parameters

Return value

First overloaded function: For a single-line edit control, the return value is always TRUE. For a multiline edit control, the return value is TRUE if the undo operation is successful, or FALSE if the undo operation fails.

Second overloaded function: The actual count of undo operations performed. If all of the Count undo operations were performed, it returns S_OK. If the method fails, it returns S_FALSE, indicating that less than Count undo operations were performed.

Description

First overloaded function: Undoes the last edit control operation in the control's undo queue.

Second overloaded function: Performs a specified number of undo operations.

SuspendUndo: Suspends undo processing.

ResumeUndo: Resumes undo processing.

Remarks

Edit controls and Rich Edit 1.0: An undo operation can also be undone. For example, you can restore deleted text with the first EM_UNDO message, and remove the text again with a second EM_UNDO message as long as there is no intervening edit operation.

Rich Edit 2.0 and later: The undo feature is multilevel so sending two EM_UNDO messages will undo the last two operations in the undo queue. To redo an operation, send the EM_REDO message.

Reference

• Defined in AfxNova/CRichEditCtx.inc:3181
• Documented in Windows/WIndows Controls/RichEdit/CRichEditCtx Class.md
• Topic: CRichEditCtx Class