TOpenDialog/zh CN

procedure TForm1.Button1Click(Sender: TObject);
    var
      s:String;
    begin
      try
      OpenDialog1.Execute;
      s := OpenDialog1.FileName;
      Form1.Caption  := s;
      Memo1.Lines.LoadFromFile(s);
      except
       on E: Exception do
        //ShowMessage( 'Error: '+ E.ClassName + #13#10 + E.Message );
        ShowMessage('忘记选择文件或者选择的文件不存在');
      end;
    end;