Lazarus GDI+ problem. Access Violation

[loaded]

Can you upload a sample image?

[Nick00]

Change the extension to emf.

[loaded]

When I save the stream objects it creates in its two methods in a file, they both have the same content. When I reset the starting positions, the result is still the same. I think it's an interesting situation.
There is probably information that the stream object created by the Adapter class has or does not have, other than the context data.
In the future, I will investigate this issue in depth. I have different trials in mind, but that's all I've got at the moment.
I would be glad if experts on the subject give their opinion.

[marcov]

I also want to have a look in time. Can sb create a bugreport with image, code and link to gdiplus units?

[loaded]

I don't know why, but some issues are stuck in my head. This is one of them, the opinion that I have reached from the research I have done;

Code: Pascal  [Select][+][-]

1. procedure TForm1.ButtonAPClick(Sender: TObject);
2. var
3.     img:IGPImage;
4.     g: IGPGraphics;
5.     Ms:TMemoryStream;
6.     Adapter:TStreamAdapter;
7.     EmfStream :IStream;
8.     test:Qword;
9. begin
10.   Ms:=TMemoryStream.Create;
11.   Ms.LoadFromFile(efp);
12.   Ms.Position:=0;
13.  
14.   Adapter:=TStreamAdapter.Create(ms);
15.  
16.   EmfStream:=Adapter as IStream; // Not the adapter class, the conversion metedo here is doing the wrong thing.
17.  
18.   img := TGPImage.Create(EmfStream);
19.   g:=TGPGraphics.Create(Image1.Canvas.Handle);
20.   g.SetPageUnit (UnitPixel);
21.   g.DrawImage(img,0,0,Image1.Width,Image1.Height);
22. end;
23.  

If we make the above "EmfStream:=Adapter as IStream;" method ourselves. We can see that the problem is fixed.

Code: Pascal  [Select][+][-]

1. procedure TForm1.ButtonAPClick(Sender: TObject);
2.     function AdapterStreamtoIStream(const AStream: TStream): IStream;
3.     var
4.       Output: IStream;
5.       MemoryPointer: Pointer;
6.       test:Qword;
7.       begin
8.         try
9.           GetMem(MemoryPointer, AStream.Size);
10.           try
11.             AStream.ReadBuffer(MemoryPointer^, AStream.Size);
12.           except
13.             FreeMem(MemoryPointer);
14.             raise;
15.           end;
16.         finally
17.         end;
18.  
19.         CreateStreamOnHGlobal(0, True, Output);
20.         try
21.           Output.Write(MemoryPointer, AStream.Size, nil);
22.           Output.Seek(0, STREAM_SEEK_SET, test);
23.           Result := Output;
24.         except
25.           Output := nil;
26.           raise;
27.         end;
28.     end;
29. var
30.     img:IGPImage;
31.     g: IGPGraphics;
32.     Ms:TMemoryStream;
33.     Adapter:TStreamAdapter;
34.     EmfStream :IStream;
35.     test:Qword;
36. begin
37.   Ms:=TMemoryStream.Create;
38.   Ms.LoadFromFile(efp);
39.   Ms.Position:=0;
40.  
41.   Adapter:=TStreamAdapter.Create(ms);
42.  
43.   EmfStream:=AdapterStreamtoIStream(Adapter.Stream);  //This code gives the impression that the adapter class is working correctly.
44.  
45.   img := TGPImage.Create(EmfStream);
46.   g:=TGPGraphics.Create(Image1.Canvas.Handle);
47.   g.SetPageUnit (UnitPixel);
48.   g.DrawImage(img,0,0,Image1.Width,Image1.Height);
49. end;
50.  

This is my last post on the subject.