指针偏移

        public static void PtrMoveSize(ref IntPtr pData, int nLength)
        {
            if (IntPtr.Size == sizeof(Int64))
                pData = new IntPtr(pData.ToInt64() + nLength);
            else
                pData = new IntPtr(pData.ToInt32() + nLength);
        }

        //结构体转指针
        public static IntPtr StructToIntPtr(Object obj1)
        {
            //得到结构体的大小
            int size = Marshal.SizeOf(obj1);
            //分配结构体大小的内存空间
            IntPtr structPtr = Marshal.AllocHGlobal(size);
            Marshal.StructureToPtr(obj1, structPtr, false);
            return structPtr;
        }
        public static IntPtr IntPtrToIntPtr(IntPtr hwdn, int nSize)
        {
            //分配结构体大小的内存空间
            IntPtr structPtr = Marshal.AllocHGlobal(nSize);
            Marshal.StructureToPtr(hwdn, structPtr, false);
            return structPtr;
        }