Mega Code Archive
How to check or uncheck a tcheckbox without causing an onclick event
<![CDATA[
Question:
My application needs to update a few checkboxes and other controls but no events shall be fired by these changes. How can I prevent those OnClick() and other events?
Answer:
Before you update the control(s), you need to ..
assign NIL to the event handler property for each control
then update the control
reassign the correct event handler - as shown in the code below.
If several controls share one event handler, it would be more elegant to have a boolean flag which you temporarily set to false and the event handler(s) would check this flag before they do anything.
procedure SetCheckBox(chk: TCheckBox; b: boolean);
var
NE: TNotifyEvent;
begin { SetCheckBox }
with chk do
begin
NE := OnClick;
OnClick := nil;
Checked := b;
OnClick := NE
end; { with chk }
end; { SetCheckBox }
]]>