EM_CANUNDO message

Determines whether there are any actions in an edit control's undo queue. You can send this message to either an edit control or a rich edit control.

Parameters

wParam

Not used; must be zero.

lParam

Not used; must be zero.

Return value

If there are actions in the control's undo queue, the return value is nonzero.

If the undo queue is empty, the return value is zero.

Remarks

If the undo queue is not empty, you can send the EM_UNDO message to the control to undo the most recent operation.

Edit controls and Rich Edit 1.0: The undo queue contains only the most recent operation.

Rich Edit 2.0 and later: The undo queue can contain multiple operations.

Rich Edit: Supported in Microsoft Rich Edit 1.0 and later. For information about the compatibility of rich edit versions with the various system versions, see About Rich Edit Controls.

Requirements

See also

EM_UNDO