Hi all,

RadTreeView is very nice control , For treeline we can give line style, color but we can't set line thickness,

I want to change thickness of Treeline can you guide me how to do it?

Workaround:
private void radButton1_Click(object sender, EventArgs e)
{
    var allNodes = radTreeView1.TreeViewElement.GetNodes().ToList();

    int row = 0;
  
    Workbook workbook = new Workbook();
    Worksheet newWorksheet = workbook.Worksheets.Add();

    foreach (var item in allNodes)
    {

        CellSelection cell = newWorksheet.Cells[row, item.Level];
        cell.SetValue(item.Text);

        cell = newWorksheet.Cells[row++, 2];
        cell.SetValue(item.Checked);

    }

    var formatProvider = new XlsxFormatProvider();


    var bytes = formatProvider.Export(workbook);
    File.WriteAllBytes(@"D:\Test.xlsx", bytes);


}

At the moment the filter predicate is called only for the root nodes. A possible workaround is to recursively apply the filter logic for the child nodes as well.
Workaround:
private void Button1_Click(object sender, EventArgs e)
{
    this.radTreeView1.TreeViewElement.FilterPredicate = this.FilterNode;
    this.radTreeView1.Filter = "Custom";
}

private bool FilterNode(RadTreeNode node)
{
    Console.WriteLine(node.Text);
    if (node.Text.Contains("Child: 3"))
    {
        return true;
    }

    Stack<RadTreeNode> children = new Stack<RadTreeNode>();
    if (node.Nodes.Count > 0)
    {
        children.Push(node);
        while (children.Count > 0)
        {
            RadTreeNode current = children.Pop();
            foreach (RadTreeNode child in current.Nodes)
            {
                if (child.Text.Contains("Child: 3"))
                {
                    return true;
                }

                children.Push(child);
            }
        }
    }

    return false;
}

Workaround:

        class CustomTreeView : RadTreeView
        {
            //Replace the default element with the custom one
            protected override RadTreeViewElement CreateTreeViewElement()
            {
                return new CustomTreeViewElement();
            }

            //Enable theming for the control
            public override string ThemeClassName
            {
                get
                {
                    return typeof(RadTreeView).FullName;
                }
            }
        }

        class CustomTreeViewElement : RadTreeViewElement
        {
            //Enable themeing for the element
            protected override Type ThemeEffectiveType
            {
                get
                {
                    return typeof(RadTreeViewElement);
                }
            }

            protected override bool ProcessContextMenu(Point location)
            {
                RadTreeNode node = this.GetNodeAt(location);
                if (node == null)
                {
                    RadContextMenu menu = new RadContextMenu();
                    RadMenuItem item = new RadMenuItem();
                    item.Text = "Add a root node";
                    menu.Items.Add(item);
                    item.Click += item_Click;
                    TreeViewContextMenuOpeningEventArgs args = new TreeViewContextMenuOpeningEventArgs(node, menu);
                    OnContextMenuOpening(args);

                    if (!args.Cancel)
                    {
                        menu.Show(this.ElementTree.Control, location);
                        return true;
                    }
                }
                return base.ProcessContextMenu(location);
            }

            private void item_Click(object sender, EventArgs e)
            {
                this.Nodes.Add(new RadTreeNode("New root"));
            }
        }

Currently we do not support binding to the ToggleState.Indeterminate state automatically because it would require a change in the behavior of the Checked property. If you use the CheckedMember, the ToggleState.Indeterminate state is represent like ToggleState.On. 

Workaround: 
Subscribe to the NodeFormatting and NodeCheckedChanged events: 
void radTreeView1_NodeFormatting(object sender, Telerik.WinControls.UI.TreeNodeFormattingEventArgs e)
{
    Child child = e.Node.DataBoundItem as Child;
    if (child != null)
    {
        e.Node.CheckState = child.Status;
    }
}

void radTreeView1_NodeCheckedChanged(object sender, Telerik.WinControls.UI.TreeNodeCheckedEventArgs e)
{
    Child child = e.Node.DataBoundItem as Child;
    if (child != null)
    {
        child.Status = e.Node.CheckState;
    }
}

Similar functionality like in KendoUI or WPF

Add e.Action in SelectedNodeChanging similar to the one in the standard TreeView.BeforeSelect event which indicates what caused the event - mouse click, key pressed, or other

To reproduce:

radTreeView1.Filter = "new";
var node = new RadTreeNode( "test" );
radTreeView1.Nodes.Add( node );
//here the node is not in the Nodes collection
if ( radTreeView1.Nodes.Contains( node ) == false )
{
 radTreeView1.Nodes.Add( new RadTreeNode( "test" ) );
}

Workaround: remove the filter, perform the desired check and restore the filter

I can type to select a node.  For example, if I click to select the Car node, then type "V", selection jumps to the "Van" node.  I can right-arrow to expand, then type "U" to select the "Useful" node.

Resolution: 
Added two new properties: KeyboardSearchEnabled and KeyboardSearchResetInterval. When set the KeyboardSearchEnabled property to true, user can navigate to an item by typing when RadTreeView is focused. You can set how long the user must wait before searching with the keyboard is reset using the KeyboardSearchResetInterval property. 

Scenario: We have an object P which has two lists of child objects of types C1 and C2.
If we create a list of P and we try to bind the tree to this list and display the two lists as child nodes, we will not succeed.

Allow setting the AutoExpand time of node when drag operation is performing.

Improve the drag and drop indicators by giving more clean user friendly design and positioning.

IMPROVE. RadTreeView - add support for DataBindings of RadTreeNode

Resolution: The feature is duplicated with feedback item ADD. RadTreeView - add support for binding the checkboxes of the nodes to a field in the data
Here is the link to item:  http://feedback.telerik.com/Project/154/Feedback/Details/112624-add-radtreeview-add-support-for-binding-the-checkboxes-of-the-nodes-to-a-field. 

Private Sub LoadTvObjectInApp()
 
        Dim objectInApps As IQueryable(Of ObjectInApp)
        objectInApps = _context.ObjectInApps.Where(Function(c) (c.ApplicatieCode = "zis") AndAlso Not (c.GroepNaam = "hulp" AndAlso c.IsSysteemObject = True))
        

When using TriStateMode with AutoCheckChildNodes, there is no way to determine whether the events are raised by a user action or by programatically checking a node.
view: CheckedMode enumeration for details