我正在使用TClientDataSet作为内存表,并且必须应用具有许多条件的过滤器.
例如,对于400 OR条件,当我尝试启用过滤器时,我收到访问冲突.
Access violation at address 4DAEDC76 in module ‘midas.dll’. Read of address 00000034.
此处发生异常:
procedure TCustomClientDataSet.AddExprFilter(const Expr: Widestring; Options: TFilterOptions); begin if FExprFilter <> nil then FDSCursor.DropFilter(FExprFilter); if Expr <> '' then with TExprParser.Create(Self,Expr,Options,[poExtSyntax],'',nil,FieldTypeMap,True) do try CheckProviderEOF; Check(FDSCursor.AddFilter(FilterData,DataSize,FExprFilter)); // ** AV HERE finally Free; end; end;
它是组件上的错误还是midas.dll的限制?
我在这些midas版本上测试了这种行为:> = 15和< = 23 我正在使用Delphi XE.
示例代码:
procedure TForm41.Button1Click(Sender: TObject); var I: Integer; FilterStr: string; begin FilterStr := '(vehicleId = -1)'; //It is just an example,the original code I can have any integer number. for I := 0 to 400 do //If I change the limit value to 40 for example,it works. FilterStr := FilterStr + ' or (vehicleId = ' + IntToStr(I) + ')'; ClientDataSet1.Filter := FilterStr; ClientDataSet1.Filtered := True; ClientDataSet1.CreateDataSet; //Error here end;
我已经尝试过使用IN语句,但是我得到了同样的错误.
我没有在互联网上找到有关这种情况的参考资料.