public RadForm1()
        {
            InitializeComponent();

                        // This XML contains a simple tree with a root node having 3 children, the first of which is intended to be Bold
            var xml = "<TreeView xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" MultiSelect=\"true\" AllowDragDrop=\"true\" LabelEdit=\"true\" AllowDrop=\"true\">  <Nodes Text=\"New Package\" Expanded=\"true\" ImageKey=\"Package\" Font=\"Microsoft Sans Serif, 8.25pt, style=Bold\">    <Tag xsi:type=\"xsd:string\">&lt;Info&gt;&lt;FullName&gt;\\New Package&lt;/FullName&gt;&lt;ObjectType&gt;Package&lt;/ObjectType&gt;&lt;IsRunnable&gt;False&lt;/IsRunnable&gt;&lt;IsContainer&gt;true&lt;/IsContainer&gt;&lt;/Info&gt;</Tag>    <Nodes Text=\"Query Engine\" ImageKey=\"QueryEngine\" Expanded=\"true\" Font=\"Microsoft Sans Serif, 8.25pt, style=Bold\">      <Tag xsi:type=\"xsd:string\">&lt;Info&gt;&lt;FullName&gt;\\Query Engine&lt;/FullName&gt;&lt;ObjectType&gt;QueryEngine&lt;/ObjectType&gt;&lt;IsRunnable&gt;true&lt;/IsRunnable&gt;&lt;IsTableEntity&gt;true&lt;/IsTableEntity&gt;&lt;IsCut&gt;false&lt;/IsCut&gt;&lt;/Info&gt;</Tag>    </Nodes>    <Nodes Text=\"Connector\" ImageKey=\"Irion.SQLServer\">      <Tag xsi:type=\"xsd:string\">&lt;Info&gt;&lt;FullName&gt;\\Connector&lt;/FullName&gt;&lt;ObjectType&gt;DBConnection&lt;/ObjectType&gt;&lt;IsCut&gt;false&lt;/IsCut&gt;&lt;/Info&gt;</Tag>    </Nodes>    <Nodes Text=\"Connector Link\" ImageKey=\"DatabaseDatalink\">      <Tag xsi:type=\"xsd:string\">&lt;Info&gt;&lt;FullName&gt;\\Connector Link&lt;/FullName&gt;&lt;ObjectType&gt;DatabaseDatalink&lt;/ObjectType&gt;&lt;IsRunnable&gt;true&lt;/IsRunnable&gt;&lt;IsTableEntity&gt;true&lt;/IsTableEntity&gt;&lt;IsCut&gt;false&lt;/IsCut&gt;&lt;/Info&gt;</Tag>    </Nodes>  </Nodes></TreeView>";

            this.radTreeView1.LoadXML(new MemoryStream(System.Text.Encoding.UTF8.GetBytes(xml)));

            //make sure that the following 2 nodes are bold:
            this.radTreeView1.Nodes[0].Nodes[0].Font = new Font("Microsoft Sans Serif", 8.25F, FontStyle.Bold, GraphicsUnit.Point, 0);
            this.radTreeView1.Nodes[0].Nodes[2].Font = new Font("Microsoft Sans Serif", 8.25F, FontStyle.Bold, GraphicsUnit.Point, 0);

            var tvx = this.radTreeView1.TreeViewXml;
        }

var xml = "<TreeView xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" MultiSelect=\"true\" AllowDragDrop=\"true\" LabelEdit=\"true\" AllowDrop=\"true\">  <Nodes Text=\"New Package\" Expanded=\"true\" ImageKey=\"Package\" Font=\"Microsoft Sans Serif; 8,25pt; style=Bold\">    <Tag xsi:type=\"xsd:string\">&lt;Info&gt;&lt;FullName&gt;\\New Package&lt;/FullName&gt;&lt;ObjectType&gt;Package&lt;/ObjectType&gt;&lt;IsRunnable&gt;False&lt;/IsRunnable&gt;&lt;IsContainer&gt;true&lt;/IsContainer&gt;&lt;/Info&gt;</Tag>    <Nodes Text=\"Query Engine\" ImageKey=\"QueryEngine\" Expanded=\"true\" Font=\"Microsoft Sans Serif; 8,25pt; style=Bold\">      <Tag xsi:type=\"xsd:string\">&lt;Info&gt;&lt;FullName&gt;\\Query Engine&lt;/FullName&gt;&lt;ObjectType&gt;QueryEngine&lt;/ObjectType&gt;&lt;IsRunnable&gt;true&lt;/IsRunnable&gt;&lt;IsTableEntity&gt;true&lt;/IsTableEntity&gt;&lt;IsCut&gt;false&lt;/IsCut&gt;&lt;/Info&gt;</Tag>    </Nodes>    <Nodes Text=\"Connector\" ImageKey=\"Irion.SQLServer\">      <Tag xsi:type=\"xsd:string\">&lt;Info&gt;&lt;FullName&gt;\\Connector&lt;/FullName&gt;&lt;ObjectType&gt;DBConnection&lt;/ObjectType&gt;&lt;IsCut&gt;false&lt;/IsCut&gt;&lt;/Info&gt;</Tag>    </Nodes>    <Nodes Text=\"Connector Link\" ImageKey=\"DatabaseDatalink\">      <Tag xsi:type=\"xsd:string\">&lt;Info&gt;&lt;FullName&gt;\\Connector Link&lt;/FullName&gt;&lt;ObjectType&gt;DatabaseDatalink&lt;/ObjectType&gt;&lt;IsRunnable&gt;true&lt;/IsRunnable&gt;&lt;IsTableEntity&gt;true&lt;/IsTableEntity&gt;&lt;IsCut&gt;false&lt;/IsCut&gt;&lt;/Info&gt;</Tag>    </Nodes>  </Nodes></TreeView>";

        Dim root As New RadTreeNode()
        root.Expanded = True
        root.Text = "Root"
        root.Name = "Root"
        Me.RadTreeView1.Nodes.Add(root)
        Dim telerikTreeNode = New RadTreeNode With
        {
            .Expanded = True,
            .Name = "Child1",
            .Text = "Child1",
            .Tag = "test",
            .Font = New Font("Arial", 12.0F, FontStyle.Regular)
        }

        Me.RadTreeView1.Nodes("Root").Nodes.Add(telerikTreeNode)
        For index = 2 To 5
            Dim child As New RadTreeNode()
            child.Text = "Child" & index
            Me.RadTreeView1.Nodes("Root").Nodes.Add(child)
        Next

    DataTable table = new DataTable();
    table.Columns.Add("ParentId", typeof(int));
    table.Columns.Add("ChildId", typeof(int));
    table.Columns.Add("ProductId", typeof(int));
    table.Columns.Add("ProductCode", typeof(string));

    table.Rows.Add(0, 1, 3, "Pr - 01");
    table.Rows.Add(1, 2, 4, "P r- 02");
    table.Rows.Add(1, 3, 5, "Pr - 03");

    this.radTreeView1.DisplayMember = "ProductCode";
    this.radTreeView1.ParentMember = "ParentId"; 
    this.radTreeView1.ChildMember = "ChildId"; 
    this.radTreeView1.ValueMember = "ProductId";
    this.radTreeView1.DataSource = table;

        public RadForm1()
        {
            InitializeComponent();

            this.radTreeView1.MultiSelect = true;
            this.radTreeView1.AllowDefaultContextMenu = true; 
        } 

        class CustomTreeViewElement : RadTreeViewElement
        { 
            protected override Type ThemeEffectiveType
            {
                get
                {
                    return typeof(RadTreeViewElement);
                }
            }

            protected override bool ProcessMouseDown(MouseEventArgs e)
            {
                if (e.Button == MouseButtons.Right)
                {
                    RadContextMenu menu = this.ContextMenu; 
                    RadTreeNode node = this.GetNodeAt(e.Location);
                    if (node!=null)
                    {
                        node.Selected = true;
                    }
                    if (node != null && node.ContextMenu != null)
                    { 
                        menu = node.ContextMenu;
                    } 
                    if (menu == null && this.AllowDefaultContextMenu)
                    {
                        menu = this.InitializeDefaultContextMenu(node);
                    } 
                    if (menu != null)
                    { 
                        RadControl parentControl = (this.ElementTree.Control as RadControl);

                        if (parentControl != null)
                        {
                            menu.ThemeName = parentControl.ThemeName;
                            menu.DropDown.RightToLeft = parentControl.RightToLeft;
                        }

                        TreeViewContextMenuOpeningEventArgs args = new TreeViewContextMenuOpeningEventArgs(node, menu, this);
                        OnContextMenuOpening(args);

                        if (!args.Cancel)
                        {
                            menu.Show(this.ElementTree.Control, e.Location);
                            return true;
                        };
                    }
                }
                return base.ProcessMouseDown(e);
            } 
        }

        class CustomTreeView : RadTreeView
        {  
            protected override RadTreeViewElement CreateTreeViewElement()
            {
                return new CustomTreeViewElement();
            }
           
            public override string ThemeClassName
            {
                get
                {
                    return typeof(RadTreeView).FullName;
                }
            }

            protected override void WndProc(ref Message m)
            {
                switch (m.Msg)
                {
                    case 0x7b:
                         
                        return;
                }

                base.WndProc(ref m);
            }
        }