Demo学习： Dialogs Anonymous Callback

DialogsDialogs Anonymous Callback

窗体回调函数使用.

1. 标准回调函数

ShowMessage(const Msg: string; CallBack: TUniDialogCallBackProc = nil)

procedure TMainForm.UniButton2Click(Sender: TObject);
begin
  ShowMessage('Message-2', CallBack1);
end;
//定义回调函数
procedure TMainForm.CallBack1(Res: Integer);
begin
  //OK返回1， 取消返回2；
  UniMemo1.Lines.Add('Result-1: '+IntToStr(Res)); 
end;

2. MessageDlg(const Msg:string; DlgType: TMsgDlgType; Buttons: TMsgDlgButtons; CallBack:TUniDialogCallBackProc)

procedure TMainForm.UniButton7Click(Sender: TObject);
begin
  MessageDlg('mbYesNo', mtConfirmation, mbYesNo, DCallBack4);
end;
procedure TMainForm.DCallBack4(Res: Integer);
begin
  case Res of
    mrYes : UniMemo1.Lines.Add('DResult: YES');
    mrNo : UniMemo1.Lines.Add('DResult: NO');
    mrOK : UniMemo1.Lines.Add('DResult: OK');
    mrCancel : UniMemo1.Lines.Add('DResult: CANCEL');
  end;
end;

2. 匿名回调函数

这种写法适合代码量少的，多了就比较乱，还是标准的看着习惯。

procedure TMainForm.UniButton6Click(Sender: TObject);
begin
  MessageDlg('Dialog3', mtConfirmation, mbYesNo,
    procedure(Res: Integer)
    begin
      case Res of
        mrYes :
          MessageDlg('Dialog4', mtConfirmation, mbYesNo,
            procedure(Res: Integer)
            begin
              case Res of
                mrYes : UniMemo1.Lines.Add('DResult: YES');
                mrNo : UniMemo1.Lines.Add('DResult: NO');
              end;
            end
          );
        mrNo : UniMemo1.Lines.Add('DResult: NO');
      end;
    end
  );
end;