Control flow
lazarus / 13-General

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rquiterio · 2009-02-10 15:31

Hi,


It’s my first app with Lazarus and I’m having  a rare situation with
it.

After returning from a function call, (it could be showmessage, for
example) the control goes to the beginning of the calling function not
to the line after the second function was called.


In this piece of code I try to validate that a customer exists and
that is currently active. But when the function Mostrar_Mensajes_Error
is executed, after returning to the calling function (the Enter event
of a textbox) the control goes to the beginning of the event, not to 
the line after where the function was called.  That makes the event to
be repeated.

I’m using Lazarus 0.9.26 beta on Windows XP SP2


Thanks in advance,



  screen.Cursor:=crhourglass;

  //Busco el cliente

  with data_qry do
  begin
     SQL.Clear;
     Close;
     SQL.Add('select
nombres,apellidos,direccion,cedula,telefono_01,');
     SQL.Add('telefono_02,estatus from clientes ');
     SQL.Add('where negocio=:negocio and cliente=:codigo ');
     Params.ParamByName('negocio').AsInteger:=StrtoInt(trim(frmmain.tx
tnegocio.text));
     Params.ParamByName('codigo').AsInteger:=StrtoInt(txtcodigo.text);
     Open;

     if RecordCount>0 then
     begin
        //Valido que el cliente este activo
        if fieldbyname('estatus').asstring='I' then
        begin
           screen.Cursor:=crdefault;
           Mostrar_Mensaje_Error('Error: ','El cliente no está
activo.',2);
           txtcodigo.SetFocus;
           Exit;
        end;

        //Paso los datos del cliente a la pantalla
        txtnombre.text      := trim(FieldByName('nombres').AsString)
+' '+
                             
 trim(FieldByName('apellidos').AsString);
        txtdireccion.text   := FieldByName('direccion').AsString ;
        txtcedula.text      := FieldByName('cedula').AsString ;
        txttelefono_01.text := FieldByName('telefono_01').AsString ;
        txttelefono_02.text := FieldByName('telefono_02').AsString ;
        txtaccion.text      := 'A'
     end
     else
     Begin
        screen.Cursor:=crdefault;

        Mostrar_Mensaje_Error('Error: ','El cliente no existe.',2);
        txtcodigo.SetFocus;
        Exit;
     End;

  end;

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cpalx · 2009-02-10 17:23

I have some similar code, and goes fine

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Martin_fr · 2009-02-10 20:31

The probable cause is in the following bit of your post "(the Enter
event of a textbox)"

and then:
       Mostrar_Mensaje_Error('Error: ','El cliente no está
activo.',2);
        txtcodigo.SetFocus;

If you are indeed in  txtcodigo.OnEnter  then setting focus to this
control, can trigger the OnEnter again.

There was a previous discussion on exactly this (either here on the
forum or on the mailing list; Sorry don't remember the details).

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rquiterio · 2009-02-10 21:08

Thanks Martin_fr for your interest

But the code is in the Enter event of another text box.  Following the
tabOrder property.

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rquiterio · 2009-02-13 23:00

If I run it on Linux (ubuntu 8.10) it goes Ok.  The problem is with
Windows