Error configuring event listener in C++ with .NET CLR support (managed and unmanaged

[fararjeh]

Hi All,
I am using AForge library to capture live video stream from an IP camera. Initially, I tested my task in a simple C# application but I should convert my code into my existing MFC C++ application. I made some progress as the following:
1. I configured the project to become compatible with .NET common run-time language
a. Right click the project and select ‘Properties’.
b. From the left panel, I selected ‘Configuration Properties’
c. Select ‘General’.
d. In ‘Common Language Runtime Support’ list select Common Language Runtime Support (/clr))
2. I added the necessary AForge DLLs to the projct. (Right click the project and select ‘References’)
3. The following is a part of my code in mfc_testDlg.h

 
#include <vcclr.h> //to use gcroot
using namespace AForge::Controls;
using namespace AForge::Video;
 
class Cmfc_testDlg : public CDialog
{
public:
    gcroot<AForge::Video::MJPEGStream^> VideoStream;
        void temp();
    void VideoStream_NewFrame(System::Object^  sender, AForge::Video::NewFrameEventArgs^ eventArgs);
}

4. The following is a part of my code in mfc_testDlg.cpp

using namespace AForge::Controls;
using namespace AForge::Video;
void Cmfc_testDlg::temp()
{    
    VideoStream = (gcnew AForge::Video::MJPEGStream());
    VideoStream->Source = "http://IP Address/img/mjpeg.cgi";
    VideoStream->Login = "User Name";
    VideoStream->Password = "Password";
    VideoStream->NewFrame += gcnew AForge::Video::NewFrameEventHandler(this, &Cmfc_testDlg::VideoStream_NewFrame);
 
    VideoStream->Start();
}
 
void Cmfc_testDlg::VideoStream_NewFrame(System::Object^  sender, AForge::Video::NewFrameEventArgs^ eventArgs)
{
    //Write Some Code
}

My code generates an error due to the line:

VideoStream->NewFrame += gcnew AForge::Video::NewFrameEventHandler(this, &Cmfc_testDlg::VideoStream_NewFrame);

This is the generated error:

error C3364: 'AForge::Video::NewFrameEventHandler' : invalid argument for delegate constructor; delegate target needs to be a pointer to a member function

It seems I couldn’t register the event listener properly in C++/with .NET CLR support. Actually I am not expert in C++ but I am fairly experience in C# and Java. Can you please suggest what I should change in my code?

Best Regards,
Abdullah

[weaknessforcats]

Operators like

new

or

gcnew

return an address or a reference to a object so the += in your gcnew line looks suspicious. Unfortunately, I am not an expert with gcnew so I may be off base.