弹出对话框MessageDlg

  MessageDlg(‘Choose a button:‘, System.UITypes.TMsgDlgType.mtInformation,
      [
        System.UITypes.TMsgDlgBtn.mbYes,
        System.UITypes.TMsgDlgBtn.mbNo,
        System.UITypes.TMsgDlgBtn.mbCancel
      ], 0,
      procedure(const AResult: TModalResult)
      begin
        if AResult = mrYES then
           ShowMessage(‘You chose Yes‘) else
        if AResult = mrNo then
           ShowMessage(‘You chose No‘) else
        if AResult = mrCancel then
           ShowMessage(‘You chose Cancel‘);
      end);