Question

I’m trying to center all message dialogs, including any exception dialogs on the parent form rather than having them always appear in the center of the screen.

I’m using Delphi 7 i note that using MessageDlgPos allows the params of X an Y to locate the dialog on screen, and thats fine for any messages i wish to display to the user. But what about the location of the exception dialogs? Can they appear in the center of the parent form as well?

Any help greatly appreciated!

Answer 1

@Rucia, my suggestion is wich you use the OnException Event from the TApplicationEvents component, and then create your own dialog using the CreateMessageDialog function.

see this sample.

procedure TForm1.ApplicationEvents1Exception(Sender: TObject; E: Exception);
var
   MyDialogMsg : TForm;
   ALeft       : Integer;
   ATop        : Integer;

begin
  //Create the dialog with the exeception message
  MyDialogMsg := CreateMessageDialog(E.Message, mtError, [mbOk]);
  try
      //Calculate the pos of the dialog using the Screen.ActiveForm and the dialog size.
      ALeft := Screen.ActiveForm.Left + (Screen.ActiveForm.Width div 2)  - (MyDialogMsg.Width div 2);
      ATop := Screen.ActiveForm.Top   + (Screen.ActiveForm.Height div 2) - (MyDialogMsg.Height div 2);
      if ALeft < 0 then ALeft := Screen.ActiveForm.Left;
      if ATop < 0  then  ATop := Screen.ActiveForm.Top;
      if (ALeft + MyDialogMsg.Width > Screen.Width) or  (ATop + MyDialogMsg.Height > Screen.Height)
      then
        begin
          ALeft := (Screen.Width - MyDialogMsg.Width) div 2;
          ATop  := (Screen.Height - MyDialogMsg.Height) div 2;
          MyDialogMsg.SetBounds (ALeft, ATop, MyDialogMsg.Width, MyDialogMsg.Height);
        end
      else
      MyDialogMsg.SetBounds(ALeft, ATop, MyDialogMsg.Width, MyDialogMsg.Height);
      //show the dialog
      MyDialogMsg.ShowModal;
  finally
   MyDialogMsg.Free;
  end;
end;