C++/CLI wrapper for native C++ dll
CodeGuru Home VC++ / MFC / C++ .NET / C# Visual Basic VB Forums Developer.com
Results 1 to 2 of 2

Thread: C++/CLI wrapper for native C++ dll

  1. #1
    Join Date
    Jul 2010
    Posts
    4

    C++/CLI wrapper for native C++ dll

    I have written an C++/Cli wrapper for a native C++ dll, but when I call some method from C# I get an System.AccessViolationException error in my C++/Cli Wrapper dll! It's necessary to marshal the unmanaged types or something else?!

    Code:
        // Wrapper.h
        
        typedef UnmanagedClass* (*Instance)(void);
        
        private:
        	UnmanagedClass *m_object; // unmanaged object	
    
        // Wrapper.cpp
        
        Wrapper:Wrapper()
        {
            HINSTANCE unmanagedLib;
            unmangedLib = LoadLibrary(SystemStringToLPCSTR(dllPath+dllName));
        
            // load instance
            Instance _createInstance = (Instance)GetProcAddress(unmangedLib, "GetInstance");
            m_object = (_createInstance)();	
        }
    
        Wrapper::~Wrapper()
        {
            //m_object->~UnmanagedClass();
            delete m_object;
            m_object = 0;
        }
    
    
        Uint32 Wrapper::SomeMethod(Uint8 *bytRecvBuffer, int &iRecvLen)
        {
            return m_object->SomeMethod(bytRecvBuffer, iRecvLen);
        }
    
        // Unmanaged Class
        
        class UnmanagedClass	
        {
        public:
        	/**
        	* Default constructor. 
        	*/
        	UnmanagedClass(void);
        	/**
        	* Default Destructor
        	*/
        	~UnmanagedClass(void);
        
            virtual Uint32 Wrapper::SomeMethod(Uint8 *bytRecvBuffer, int &iRecvLen);
        };
    
        // export the UnmanagedClass object
        extern "C" _declspec(dllexport) UnmanagedClass* GetInstance();
    
        // UnamangedClass.cpp
        
        UnamangedClass::~UnamangedClass(void)
        {
        	if (UnamangedClassDLL != NULL)
        		FreeLibrary(UnamangedClassDLL);
        
        	UnamangedClassDLL = NULL;
        }
    
        extern "C" _declspec(dllexport) UnmanagedClass* GetInstance()
        {
        
        	return new UnmanagedClass();
        }
    When I call at example SomeMethod from C# I get the error in C++/Cli dll!
    (I included the C++/cli dll with add reference in C sharp project and create the Wrapper object)


    Thank you for your help!



    greets

  2. #2
    Join Date
    Jul 2002
    Posts
    2,513

    Re: C++/CLI wrapper for native C++ dll

    How do you call this method from C#? Why C++/CLI method has unsafe Uint8* parameter? Use array<Byte>^ instead, it is translated to Byte[] in C#. C++/CLI wrapper must have pure .NET interface, without using unsafe pointers.

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


Windows Mobile Development Center


Click Here to Expand Forum to Full Width

This is a CodeGuru survey question.


Featured


HTML5 Development Center