Author: William Gerbert

Disabling an event handler once it has executed once

Answer:

Have you ever wanted to keep an event from firing once it has executed once? Simply 
set the event handler method to nil in the body of the method. For instance, let's 
say you want to disable an OnClick for a button once the user has pressed it. 
Here's the code to do that:

1   procedure Button1OnClick;
2   begin
3     Button1.OnClick := nil;
4   end;