Menu 按滑鼠右鍵觸發事件

type   TForm1 = class(TForm)  
  private    
    procedure MenuRButtonUp(var Msg: TMessage); message WM_MENURBUTTONUP;  
  public    
  { Public declarations }  
end;

procedure MenuRButtonUp(var Msg:TMessage);
begin
  ShowMessage('Right Click');
end;