UnDo in a memo field

Problem/Question/Abstract:

UnDo in a memo field

Answer:

If you have a pop-up menu in a TMemo, and put shortcuts on it for the Cut, Copy, Paste, then you can handle those events, and call CuttoClipBoard, CopytoClipBoard, etc.

However, if you put an Undo option onto your pop-up menu (normally Ctrl-Z), how do you instruct the TMemo to do the Undo?

If the built-in undo is sufficient, you can get it easier than a Ctrl+Z:


Memo1.Perform(EM_UNDO, 0, 0);


To check whether undo is available so as to enable/disable
an undo menu item:


Undo1.Enabled := Memo1.Perform(EM_CANUNDO, 0, 0) <> 0;