An application sends a WM_UNDO message to an edit control to undo the last operation. When this message is sent to an edit control, the previously deleted text is restored or the previously added text is deleted.
WM_UNDO
wParam = 0; // not used; must be zero
lParam = 0; // not used; must be zero
This message has no parameters.
If the message succeeds, the return value is TRUE; otherwise, it is FALSE.
Windows NT: Requires version 3.1 or later.
Windows: Requires Windows 95 or later.
Windows CE: Requires version 1.0 or later.
Header: Declared in winuser.h.
Edit Controls Overview, Edit Control Messages, WM_CLEAR, WM_COPY, WM_CUT, WM_PASTE