Question: I want to display a menu when a user clicks a button. How do I do this?

Answer: There are a number of different ways to do this, but one of the easiest is to:

1. Assign a popup Menu to the PopupMenu property of a button.

2. Set the popup menu's AutoPopup property to False.

3. Add code to the button's OnClick event to position and open the menu, as shown in the following code sample:

   procedure TForm1.Button1Click(Sender: TObject);
   var
      p : TPoint;
   begin
      with Sender as TButton do
      begin
         if PopupMenu = nil then
            beep
         else
            begin
               GetCursorPos( p );
               p.x := Left + 1;
               p.y := Top + Height + 1;
               p := Self.ClientToScreen( p );
               PopupMenu.popup( p.x, p.y );
            end;
      end;
   end;

Use care to typecast Sender correctly; otherwise, you may receive unexpected exceptions. For example, casting Sender as a TSpeedButton when running it from a TButton generates an Invalid Typecast exception when you click the button.