Opc.Ua.Server.CoreNodeManager.SetMonitoringMode C# (CSharp) Method

        public void SetMonitoringMode(
            OperationContext      context,
            MonitoringMode        monitoringMode,
            IList<IMonitoredItem> monitoredItems, 
            IList<bool>           processedItems,
            IList<ServiceResult>  errors)
        {

            if (context == null)        throw new ArgumentNullException("context");
            if (monitoredItems == null) throw new ArgumentNullException("monitoredItems");
            if (errors == null)         throw new ArgumentNullException("errors");

            try
            {
                m_lock.Enter();

                for (int ii = 0; ii < errors.Count; ii++)
                {                  
                    // skip items that have already been processed.
                    if (processedItems[ii] || monitoredItems[ii] == null)
                    {
                        continue;
                    }
  
                    // check if the node manager created the item.                    
                    if (!Object.ReferenceEquals(this, monitoredItems[ii].NodeManager))
                    {
                        continue;
                    }

                    // owned by this node manager.
                    processedItems[ii]  = true;
                    
                    // validate monitored item.
                    MonitoredItem monitoredItem = null;

                    if (!m_monitoredItems.TryGetValue(monitoredItems[ii].Id, out monitoredItem))
                    {
                        errors[ii] = StatusCodes.BadMonitoredItemIdInvalid;
                        continue;
                    }

                    if (!Object.ReferenceEquals(monitoredItem, monitoredItems[ii]))
                    {
                        errors[ii] = StatusCodes.BadMonitoredItemIdInvalid;
                        continue;
                    }

                    // update monitoring mode.
                    MonitoringMode previousMode = monitoredItem.SetMonitoringMode(monitoringMode);

                    // need to provide an immediate update after enabling.
                    if (previousMode == MonitoringMode.Disabled && monitoringMode != MonitoringMode.Disabled)
                    {
                        DataValue initialValue = new DataValue();

                        initialValue.ServerTimestamp = DateTime.UtcNow;
                        initialValue.StatusCode      = StatusCodes.BadWaitingForInitialData;
                        
                        // read the initial value.
                        Node node = monitoredItem.ManagerHandle as Node;
                        
                        if (node != null)
                        {
                            ServiceResult error = node.Read(context, monitoredItem.AttributeId, initialValue);

                            if (ServiceResult.IsBad(error))
                            {
                                initialValue.Value = null;
                                initialValue.StatusCode = error.StatusCode;
                            }
                        }
                                
                        monitoredItem.QueueValue(initialValue, null);
                    }
            
                    // modify the item attributes.   
                    m_samplingGroupManager.ModifyMonitoring(context, monitoredItem);
                  
                    // item has been modified successfully. 
                    // errors updating the sampling groups will be reported in notifications.
                    errors[ii] = StatusCodes.Good;
                }
            }
            finally
            {
                m_lock.Exit();
            } 

            // update all sampling groups.
            m_samplingGroupManager.ApplyChanges();
        }
        #endregion