CgwMonitorManage.Ivs.IvsVideoMonitor.StartReceiveVideo C# (CSharp) Method

        public SmcErr StartReceiveVideo(string cameraNo)
        {
            NLogEx.LoggerEx logEx = new NLogEx.LoggerEx(log);
            logEx.Trace("Enter: IvsVideoMonitor.StartReceiveVideo({0}).", cameraNo);
            SmcErr err = new CgwError();
            int handle;
            logEx.Trace("Call ivsSdkClient.StartRealPlayCBRaw({0}).", cameraNo);
            int result = this.ivsSdkClient.StartRealPlayCBRaw(cameraNo, out handle);

            //如果不为0，表示预览失败
            if (result != CgwConst.IVS_SDK_SUCCESS_TAG)
            {
                err.SetErrorNo(CgwError.START_RECEIVE_VIDEO_FAILED);
                logEx.Error("Start Receive camera video data failed.Camera No:{0}.Ivs sdk error code:{1}", cameraNo, result);
                return err;
            }
            else
            {
                logEx.Info("Start Receive camera video data success.Camera No:{0},Handle:{1}.", cameraNo, handle);
            }

            //预览成功，需要停止原来的预览，并将预览句柄添加到缓存
            //需要停止的预览句柄
            int needToStopHandel = CgwConst.START_RECEIVE_VIDEO_DATA_FAILED;
            if (this.handelOperateLock.TryEnterWriteLock(CgwConst.ENTER_LOCK_WAIT_TIME))
            {
                try
                {
                    //如果预览句柄已经存在，删除掉原来的句柄,用新的句柄替换
                    if (this.cameraVideoHandeDic.ContainsKey(cameraNo))
                    {
                        needToStopHandel = this.cameraVideoHandeDic[cameraNo];
                        this.videoHandleCameraDic.Remove(needToStopHandel);
                        this.cameraVideoHandeDic.Remove(cameraNo);
                    }
                    this.cameraVideoHandeDic.Add(cameraNo, handle);
                    MediaDataSender mediaDataSender = new MediaDataSender(cameraNo, this.dataCallBack);
                    this.videoHandleCameraDic.Add(handle, mediaDataSender);
                }
                finally
                {
                    this.handelOperateLock.ExitWriteLock();
                }
            }

            //重新预览后，更新了预览句柄，需要将原来的预览停止，放在handelOperateLock外面，防止长时间占用锁
            if (needToStopHandel != CgwConst.START_RECEIVE_VIDEO_DATA_FAILED)
            {
                result = this.ivsSdkClient.StopRealPlay(needToStopHandel);
                //如果不为0，表示停止原来的预览失败，只记录日志，不返回错误，不设置错误码
                if (result != CgwConst.IVS_SDK_SUCCESS_TAG)
                {
                    logEx.Error("Get a new preview success. But stop old preview failed.CameraNo:{0},Ivs sdk error code:{0}", cameraNo, result);
                    return err;
                }
            }

            return err;
        }