C# DllExport -Can't use AForge functions

Question

I am trying to export code from a function in C# to Delphi. I used DllExport with stdcall convention and made some tests :it works. I tested for integers and strings as params. The problem occurs when I try to use a class from Aforge library in C#. Delphi returns an error: "External Exception E0434F4D".

public class ProcessClass
{
    [DllExport(CallingConvention=CallingConvention.StdCall)]
    public static void ProcessImage()
    {
        try
        {
            Erosion erosion = new Erosion();
        }
        catch (Exception Ex)
        {
        }
    }
}

Delphi code:

procedure ProcessImage; stdcall; external 'C:\Users\Reznicencu Bogdan\source\repos\OCR\OCR\bin\x86\Release\OCR.dll';

procedure TForm1.FormCreate(Sender: TObject);
begin
  ProcessImage;
end;

The error apears at Erosion.Actually every function I use from Aforge library generates an error. I used Try/catch because I know Delphi can't catch exceptions from unmanaged code but it still doesn't work. How can I solve this error?

The event log says: First chance exception at $767EDDC2. Exception class EExternalException with message 'External exception E0434F4D'. Process Project1.exe (9528)

Answer 1

The problem appears to be related to the location of the AForge DLLs. If you place those, and your class library DLL, in the same directory as your Delphi executable then the error disappears.

Perhaps there is some other way to tell AForge where to locate its DLLs. I will leave that as an exercise for the reader to investigate.