public int FileTransferOpen(ref IntPtr phTransfer, BVCU_File_TransferParam transferParam, object userData) { IntPtr pParam = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(BVCU_File_TransferParam))); Marshal.StructureToPtr(transferParam, pParam, false); int rc = BVCU.ManagedLayer_BVFileTransferOpen(m_sdkOperator.m_bvcuSdkHandle, ref phTransfer, pParam); timerGetTransInfo.Start(); Marshal.FreeHGlobal(pParam); return(rc); }