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);
}