c#调用C++ 获取数组的指针，然后将指针的首字节传入Com

                byte[] buffer = new byte[100];
                GCHandle hObject = GCHandle.Alloc(buffer, GCHandleType.Pinned);
                IntPtr ptr = hObject.AddrOfPinnedObject();
                byte[] arrBuf = new byte[1];
                Marshal.Copy(ptr, arrBuf, 0, 1);

                mediaFileReader.GetVideFrameBuffer(sFileName, frameIndex, BufferSize, ref arrBuf[0], out videoWidth, out videoHeight,
                                                   out pulRowPitch);