Delphi 11.1 Fastreports / TeeChart issue

Question

I have created an app for users to create reports in FastReports with charts. The standalone exe works fine. However when I incorporate the same code in a DLL, adding or editing a chart generates the following error:

exception message  : Access violation at address 092E95C7 in module 'NEWREPORTDLL.DLL'. Write of address 00000000.

main thread ($5c54):
092e95c7 +007 NEWREPORTDLL.DLL System             18097   +5 TObject.InitInstance
096bcdc4 +010 NEWREPORTDLL.DLL Winapi.GDIPAPI      7277   +1 TGdiplusBase.NewInstance
092e9ba3 +007 NEWREPORTDLL.DLL System             19251   +5 @ClassCreate
096d0df6 +00e NEWREPORTDLL.DLL Winapi.GDIPOBJ      4497   +0 TGPGraphics.Create
09b9088c +010 NEWREPORTDLL.DLL VCLTee.TeeGDIPlus   1274   +1 TGDIPlusCanvas.RecreateGraphics
09b909a8 +048 NEWREPORTDLL.DLL VCLTee.TeeGDIPlus   1305   +6 TGDIPlusCanvas.GetGraphics
09b90dee +0d6 NEWREPORTDLL.DLL VCLTee.TeeGDIPlus   1468  +20 CheckGraphics
09b90ea6 +0ae NEWREPORTDLL.DLL VCLTee.TeeGDIPlus   1504  +31 TGDIPlusCanvas.InitWindow
09af5050 +0a8 NEWREPORTDLL.DLL VCLTee.TeeProcs     2243  +12 InnerDraw
09af517c +010 NEWREPORTDLL.DLL VCLTee.TeeProcs     2279   +7 TCustomTeePanel.Draw
09af64f6 +0ae NEWREPORTDLL.DLL VCLTee.TeeProcs     3322  +19 TCustomTeePanel.NonBufferDraw
09af61c9 +02d NEWREPORTDLL.DLL VCLTee.TeeProcs     3209   +3 TCustomTeePanel.DrawToMetaCanvas
09ba996f +1a3 NEWREPORTDLL.DLL frxChart            1032  +26 TfrxChartView.Draw
0978e70c +044 NEWREPORTDLL.DLL frxClass           12836   +2 TfrxReportComponent.InteractiveDraw

Attempting to add a series results in this:

exception message  : Access violation at address 092E95C7 in module 'NEWREPORTDLL.DLL'. Write of address 00000000.

main thread ($5c54):
092e95c7 +007 NEWREPORTDLL.DLL System                     18097   +5 TObject.InitInstance
096bcdc4 +010 NEWREPORTDLL.DLL Winapi.GDIPAPI              7277   +1 TGdiplusBase.NewInstance
092e9ba3 +007 NEWREPORTDLL.DLL System                     19251   +5 @ClassCreate
096d3c88 +010 NEWREPORTDLL.DLL Winapi.GDIPOBJ              6665   +0 TGPFont.Create
09b91f62 +23a NEWREPORTDLL.DLL VCLTee.TeeGDIPlus           2020  +53 TGDIPlusCanvas.DoChangedFont
09ad1958 +070 NEWREPORTDLL.DLL VCLTee.TeCanvas             5547  +19 TTeeCanvas.AssignFontSize
09ad198c +018 NEWREPORTDLL.DLL VCLTee.TeCanvas             5552   +1 TTeeCanvas.AssignFont
09af54c9 +025 NEWREPORTDLL.DLL VCLTee.TeeProcs             2616   +4 TCustomTeePanel.TryAssignFont
09b99697 +07b NEWREPORTDLL.DLL VCLTee.TeeGalleryPanel       695   +8 TGalleryChart.SetTitleFontSize

DLL Project source is this:

library NewReportDLL;

uses
  ShareMem,
  System.SysUtils,
  System.Classes,
  Winapi.Windows,
  Winapi.Messages,
  System.Variants,
  System.IOUtils,
  Vcl.Graphics,
  VCL.Themes,
  Vcl.Controls,
  Vcl.Forms,
  Vcl.Dialogs,
  uGlobals in 'uGlobals.pas',
  uDMRPT in 'uDMRPT.pas' {DMRPT: TDataModule},
  ufrmRptTest in 'ufrmRptTest.pas' {frmReport};


{$R *.res}

function RunReport( cmd: PAnsiChar  ):integer;
var  
     frmReport: TfrmReport;
begin
   Application.CreateForm(TDMRPT, DMRPT);   // create datamodule

   Application.CreateForm(TfrmReport, frmReport);  // create form

   try
      frmReport.ShowModal;
   finally
      freeandnil(frmReport);
      freeandnil( DMRpt );
   end;
end;

   Exports
      RunReport name 'RunReport';
end.

Environment:

Delphi 11.1 FastReports 2023.1.3 Standard Delphi 11.1 TeeChart version included with Delphi

I atempted to install the Steema TeeChart VCL/FMX v2023 Standard to see if it resolved the issue. It fails to install on 11.1.

Any suggestions as to how to eliminate the error would be appreciated.

Answer 1

It might be a problem related to using Microsoft GDI+ inside a dll.

You might want to try the following in the caller exe: https://steema.com/wp/blog/2014/03/12/teechart-and-gdi-inside-a-dll/

or, disabling GDI+ inside the dll, before the charts are created:

TeeDefaultCanvas:='';

regards ! david