Stack overrun in field.OnChange

Ludek · Post by **Ludek** » Tue 25 Apr 2006 16:08

I'm getting stack overrun, when I change a field value in an "onchange" event of another field of the same dataset, for example:

Code: Select all

procedure TTestF.QGruppePreislisteaufschlagChange(Sender: TField);
begin
  inherited;
  QGruppePreislisteDB.AsFloat := 1;
end;

if QGruppePreislisteaufschlag is a column in a TDBGrid, user writes some value to this column and presses ENTER or something like it to jump from the currently edited column, a stackoverrun comes. could you help me? I'm using the newest "3.70.1.26" SDAC version and delphi 2006 update pack 1. thx.

Guest · Post by **Guest** » Wed 26 Apr 2006 05:58

Note: the same code works fine using Delphi 7 and al older SDAC version!!

Jackson · Post by **Jackson** » Wed 26 Apr 2006 08:37

This is VCL problem(Unit DBGrids.pas, TGridDataLink.RecordChanged method). Please install Borland Developer Studio 2006 Update 2 to correct this problem.

Ludek · Post by **Ludek** » Wed 26 Apr 2006 16:23

I'm having still the same problem, although i installed the update pack 2

I'll send you sources a small executable, as soon as I have one...

Ludek · Post by **Ludek** » Wed 26 Apr 2006 16:49

That's it:
dfm file:

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object TestF: TTestF
  Left = 245
  Top = 148
  Caption = 'Gruppen'
  ClientHeight = 465
  ClientWidth = 810
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -11
  Font.Name = 'Tahoma'
  Font.Style = []
  OldCreateOrder = True
  OnCreate = FormCreate
  PixelsPerInch = 96
  TextHeight = 13
  object DBGGruppePreisliste: TDBGrid
    Left = 0
    Top = 0
    Width = 810
    Height = 465
    Align = alClient
    DataSource = DSGruppePreisliste
    TabOrder = 0
    TitleFont.Charset = DEFAULT_CHARSET
    TitleFont.Color = clWindowText
    TitleFont.Height = -11
    TitleFont.Name = 'Tahoma'
    TitleFont.Style = []
    Columns = 
  end
  object QGruppePreisliste: TMSQuery
    Connection = MSConnection1
    SQL.Strings = (
      'select 0.0 as db, 0.0 as aufschlag'
      'from sysdatabases')
    CachedUpdates = True
    Left = 488
    Top = 96
    object QGruppePreislisteaufschlag: TFloatField
      FieldName = 'aufschlag'
      OnChange = QGruppePreislisteaufschlagChange
      DisplayFormat = '0.00 %'
    end
    object QGruppePreislistedb: TFloatField
      FieldName = 'db'
      DisplayFormat = '0.00 %'
    end
  end
  object DSGruppePreisliste: TDataSource
    DataSet = QGruppePreisliste
    Left = 456
    Top = 96
  end
  object MSConnection1: TMSConnection
    Database = 'master'
    Authentication = auServer
    Username = 'sa'
    Password = ''
    Server = '.'
    Connected = True
    Left = 408
    Top = 168
  end
end

pas file

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unit TestU;
interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  Db, ImgList, Menus, DBCtrls, ComCtrls, ToolWin,
  ExtCtrls, Grids, DBGrids, StdCtrls, Mask, ActnList, Buttons,
  DBAccess, MSAccess, MemDS, ActnMan, ActnColorMaps, ActnCtrls,
  ActnMenus;

type
  TTestF = class(TForm)
    QGruppePreisliste: TMSQuery;
    DSGruppePreisliste: TDataSource;
    QGruppePreislisteaufschlag: TFloatField;
    QGruppePreislistedb: TFloatField;
    DBGGruppePreisliste: TDBGrid;
    MSConnection1: TMSConnection;
    procedure FormCreate(Sender: TObject);
    procedure QGruppePreislisteaufschlagChange(Sender: TField);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  TestF: TTestF;

implementation

{$R *.DFM}

procedure TTestF.FormCreate(Sender: TObject);
begin
  inherited;
  QGruppePreisliste.Open;
end;

procedure TTestF.QGruppePreislisteaufschlagChange(Sender: TField);
begin
  inherited;
  QGruppePreislisteDB.AsFloat := 1;
end;

end.

simply compile it, enter a new number in the grid and press ENTER or TAB. The executable crashes.

Ludek · Post by **Ludek** » Thu 27 Apr 2006 08:30

This f***ing change in TDBGridDataLink is written in
http://qc.borland.com/wc/qcmain.aspx?d=2633
Who is Jeff Overcash and where I find him? I'm gonna kill this stupid boy!!

[/url]

Stack overrun in field.OnChange

Stack overrun in field.OnChange

Ludek