typedef bool (CALLBACK *CareffReceive)(char *pBuf, int nBufSize);

CareffReceive m_Call ;  //回复信息的回调函数
bool m_CallTrue=false;

extern "C"__declspec(dllexport)BOOL WINAPI CareffCallback(CareffReceive InfoReceive)
{
 m_Call = InfoReceive;
 //int i=1001;
 //char * a = "hello";
 //m_Call(a,i);   //recv 为 char *, nLen 为 int
 m_CallTrue=true;
 return m_CallTrue;
 //m_RecInfoCall(recv,nLen);   //recv 为 char *, nLen 为 int
}

 [DllImport("CDLLTools.dll", EntryPoint = "CareffCallback")]
        static extern bool CareffCallback(CareffdelegateCall fa);
        public delegate void CareffdelegateCall(string buf, int size);

        public static void CareffDLLReturn(string sInfo, int iKey)
        {
            Console.ForegroundColor = ConsoleColor.Red;
            Console.WriteLine("CareffDLLReturn iKey=" + iKey.ToString() + ":sInfo=" + sInfo + "");
            Console.ForegroundColor = ConsoleColor.White;
            System.Threading.Thread.Sleep(1000);
            return;
        }

  CareffCallback(CareffDLLReturn);