unit Unit1;    interface    uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls;    type
  TForm1 = class(TForm)
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
    procedure OnMessage(var Msg: TMsg; var Handled: Boolean);
  public
    { Public declarations }
  end;    var
  Form1: TForm1;    implementation    {$R *.DFM}    procedure TForm1.OnMessage(var Msg: TMsg; var Handled: Boolean);
begin
  case Msg.message of
    WM_SYSCOMMAND:
      begin //系統列 Menu 才有用
        case Msg.wParam of
          SC_RESTORE: ShowMessage('m還原');
          SC_CLOSE: ShowMessage('m關閉');
          SC_MINIMIZE: ShowMessage('m最小化');
          SC_MAXIMIZE: ShowMessage('m最大化');
          SC_MOVE: ShowMessage('m移動');
        end;
      end;
  end;      case Msg.message of
    WM_NCLBUTTONDOWN:
      begin //右上角按鈕
        case Msg.wParam of
          8: ShowMessage('btn最小化');
          9: ShowMessage('btn最大化');
          20: ShowMessage('btn關閉');
        end;
      end;
  end;
  inherited;
end;    procedure TForm1.FormCreate(Sender: TObject);
begin
  Application.OnMessage := onMessage;
end;    end.