Delphi Non-Blocking MessageDialog Example How?

Question

I have problem using FMX.Platform.IFMXDialogServiceAsync

This is my procedure:

procedure TFormMain.btnLogoutClick(Sender: TObject);
var
  ASyncService : IFMXDialogServiceASync;

begin

  ASyncService.MessageDialogAsync('Do you want to logout?', TMsgDlgType.mtInformation,
    [System.UITypes.TMsgDlgBtn.mbYes, System.UITypes.TMsgDlgBtn.mbNo],
    TMsgDlgBtn.mbNo,
    0,
    procedure(const AResult: TModalResult)
    begin
      case AResult of
      mrYes:
        begin
          Close;
        end;
      mrNo:
        begin
        // pressed no
        end;
      end;
    end
  );

end;

Below is Error that Pop-up:

Access violation at address
A29FC4F2, accessing address
00000000.

Tried directly into Android Device and Error show whenever this procedure triggered. Looked to Embarcadero Documentation but they didn't provide an example for this.

Someone written some example that I use above http://c2design5sh.blogspot.co.id/2016/05/rad-studio-dx-101-berlin-dialog-api.html

Is there anyone can tell on how to do new way MessageDialog in Android?, because I found MessageDlg going deprecated.

You're using a variable that is not initialized. You just declare a variable ASyncService to exist in your method. Then you use it without assigning something to it first. You should stick to your tutorial more closely. And yes, the compiler doesn't even bother telling you that your code is wrong, which is pretty sad. — Günther the Beautiful
– Günther the Beautiful, Commented Dec 19, 2016 at 8:32
you right!, I removed that "if" because I don't think it was necessary, thanks!!!, its solved! — Eldi Munggaran
– Eldi Munggaran, Commented Dec 19, 2016 at 10:11

David Heffernan · Accepted Answer · 2016-12-19 08:41:55Z

6

You simply need to use the code in the article you linked to. You failed to do so. The example code has this form:

var
  ASyncService : IFMXDialogServiceASync;
....
if TPlatformServices.Current.SupportsPlatformService(IFMXDialogServiceAsync, IInterface (ASyncService)) then
begin
  ASyncService.MessageDialogAsync(....);
end;

Your code fails to assign to the ASyncService variable. Hence the runtime error.

answered Dec 19, 2016 at 8:41

David Heffernan

616k46 gold badges1.1k silver badges1.5k bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Delphi Non-Blocking MessageDialog Example How?

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related