Quickstarts.HistoricalEvents.Client.SelectTypeDlg.BrowseTV_BeforeExpand C# (CSharp) Method

        private void BrowseTV_BeforeExpand(object sender, TreeViewCancelEventArgs e)
        {
            try
            {
                ReferenceDescription reference = (ReferenceDescription)e.Node.Tag;
                e.Node.Nodes.Clear();

                // browse HasEventSource to display the sources but it won't be possible to select them.
                BrowseDescription nodeToBrowse = new BrowseDescription();

                nodeToBrowse.NodeId = Opc.Ua.ObjectTypeIds.BaseEventType;
                nodeToBrowse.BrowseDirection = BrowseDirection.Forward;
                nodeToBrowse.ReferenceTypeId = ReferenceTypeIds.HasSubtype;
                nodeToBrowse.IncludeSubtypes = false;
                nodeToBrowse.NodeClassMask = 0;
                nodeToBrowse.ResultMask = (uint)BrowseResultMask.All;

                if (reference != null)
                {
                    nodeToBrowse.NodeId = (NodeId)reference.NodeId;
                }
                
                // add the childen to the control.
                ReferenceDescriptionCollection references = FormUtils.Browse(m_session, nodeToBrowse, false);
                
                for (int ii = 0; ii < references.Count; ii++)
                {
                    reference = references[ii];

                    // ignore out of server references.
                    if (reference.NodeId.IsAbsolute)
                    {
                        continue;
                    }

                    TreeNode child = new TreeNode(reference.ToString());
                    child.Nodes.Add(new TreeNode());
                    child.Tag = reference;

                    e.Node.Nodes.Add(child);
                }
            }
            catch (Exception exception)
            {
                ClientUtils.HandleException(this.Text, exception);
            }
        }
        #endregion