Author: Tomas Rutkauskas

I want to use a TMemo as a FIFO, and every time a new string is written to the 
memo, the OnChange event will be triggered. In the OnChange event I will do my work 
on the string and as the last thing make a memo.delete(0) so that the next string 
in the memo will move to line 0. My question is now, is this a right thing to do? I 
suppose that it will make a recursive call to the OnChange event and that I in this 
way have a "system" that will empty my memo as fast as possible.

Answer:

The trick is to save, wipe, and restore the event value:
1   
2   procedure TForm1.Memo1Change(Sender: TObject);
3   var
4     Save: TNotifyEvent;
5   begin
6     Save := Memo1.OnChange; {Save}
7     Memo1.OnChange := nil; {Erase}
8     Memo1.Lines.Delete(0);
9     Memo1.OnChange := Save; {Restore}
10  end;