Opc.Ua.Server.DataChangeMonitoredItem.ValueChanged C# (CSharp) Method

        public void ValueChanged(ISystemContext context)
        {
            DataValue value = new DataValue();

            ServiceResult error = m_source.Node.ReadAttribute(context, m_attributeId, NumericRange.Empty, null, value);

            if (ServiceResult.IsBad(error))
            {
                value = new DataValue(error.StatusCode);
            }

            value.ServerTimestamp = DateTime.UtcNow;

            QueueValue(value, error);
        }
        #endregion

        /// <summary>
        /// Handles change events raised by the node.
        /// </summary>
        /// <param name="context">The system context.</param>
        /// <param name="state">The node that raised the event.</param>
        /// <param name="masks">What caused the event to be raised</param>
        public void OnNodeChange(ISystemContext context, NodeState state, NodeStateChangeMasks masks)
        {
            if (m_monitoredItems != null)
            {
                for (int ii = 0; ii < m_monitoredItems.Count; ii++)
                {
                    DataChangeMonitoredItem monitoredItem = m_monitoredItems[ii];

                    // check if the node has been deleted.
                    if ((masks & NodeStateChangeMasks.Deleted) != 0)
                    {
                        monitoredItem.QueueValue(null, StatusCodes.BadNodeIdUnknown);
                        continue;
                    }

                    if (monitoredItem.AttributeId == Attributes.Value)
                    {
                        if ((masks & NodeStateChangeMasks.Value) != 0)
                        {
                            monitoredItem.ValueChanged(context);
                        }
                    }
                    else
                    {
                        if ((masks & NodeStateChangeMasks.NonValue) != 0)
                        {
                            monitoredItem.ValueChanged(context);
                        }
                    }
                }
            }
        }