public int InitSDK() { //initialize disCallback = new XMSDK.fDisConnect(DisConnectBackCallFunc); GC.KeepAlive(disCallback); int bResult = XMSDK.H264_DVR_Init(disCallback, this.Handle); //he messages received in SDK from DVR which need to upload, such as alarm information,diary information,may do through callback function msgcallback = new XMSDK.fMessCallBack(MessCallBack); XMSDK.H264_DVR_SetDVRMessCallBack(msgcallback, this.Handle); XMSDK.H264_DVR_SetConnectTime(5000, 3); return(bResult); }