How to reproduce:
public partial class RadForm1 : Telerik.WinControls.UI.RadForm
{
    private BindingList<TreeViewDataObject> data;
    public static int Id = 0;

    public RadForm1()
    {
        InitializeComponent();

        var theme = new FluentTheme();
        ThemeResolutionService.ApplicationThemeName = theme.ThemeName;

        this.data = new BindingList<TreeViewDataObject>();


        for (int i = 1; i <= 5; i += 1)
        {
            Id++;
            TreeViewDataObject root = new TreeViewDataObject()
            {
                Id = Id,
                ParentId = -1,
                Name = "Root: " + i
            };

            this.data.Add(root);

            for (int j = 1; j <= 3; j++)
            {
                Id++;
                TreeViewDataObject child = new TreeViewDataObject()
                {
                    Id = Id,
                    ParentId = root.Id,
                    Name = "Child: " + Id
                };

                this.data.Add(child);

                for (int K = 1; K <= 5; K++)
                {
                    Id++;

                    TreeViewDataObject c = new TreeViewDataObject()
                    {
                        Id = Id,
                        ParentId = child.Id,
                        Name = "Child: " + Id
                    };

                    this.data.Add(c);
                }
            }
        }

        this.radTreeView1.DataSource = this.data;
        this.radTreeView1.DisplayMember = "Name";
        this.radTreeView1.ParentMember = "ParentId";
        this.radTreeView1.ChildMember = "Id";
        this.radTreeView1.RelationBindings.Add(new RelationBinding(this.data, "Name", "ParentId", "Id"));

        this.radTreeView1.ExpandAll();

        this.radTreeView1.TreeViewElement.AllowEdit = true;
        this.radTreeView1.TreeViewElement.AllowAdd = true;
        this.radTreeView1.TreeViewElement.AllowRemove = true;
    }
}

  public class TreeViewDataObject
    {
        public int Id { get; set; }

        public int ParentId { get; set; }

        public string Name { get; set; }
    }

Workaround: Handle the ContextMenuOpening event and add logic for creating a new record in the data source object
public partial class RadForm1 : Telerik.WinControls.UI.RadForm
{
    private BindingList<TreeViewDataObject> data;
    private int id = 0;

    public RadForm1()
    {
        InitializeComponent();

        var theme = new FluentTheme();
        ThemeResolutionService.ApplicationThemeName = theme.ThemeName;

        this.data = new BindingList<TreeViewDataObject>();


        for (int i = 1; i <= 5; i += 1)
        {
            id++;
            TreeViewDataObject root = new TreeViewDataObject()
            {
                Id = id,
                ParentId = -1,
                Name = "Root: " + i
            };

            this.data.Add(root);

            for (int j = 1; j <= 3; j++)
            {
                id++;
                TreeViewDataObject child = new TreeViewDataObject()
                {
                    Id = id,
                    ParentId = root.Id,
                    Name = "Child: " + id
                };

                this.data.Add(child);

                for (int K = 1; K <= 5; K++)
                {
                    id++;

                    TreeViewDataObject c = new TreeViewDataObject()
                    {
                        Id = id,
                        ParentId = child.Id,
                        Name = "Child: " + id
                    };

                    this.data.Add(c);
                }
            }
        }

        this.radTreeView1.DataSource = this.data;
        this.radTreeView1.DisplayMember = "Name";
        this.radTreeView1.ParentMember = "ParentId";
        this.radTreeView1.ChildMember = "id";
        this.radTreeView1.RelationBindings.Add(new RelationBinding(this.data, "Name", "ParentId", "id"));

        this.radTreeView1.ExpandAll();
        
        this.radTreeView1.ContextMenuOpening += RadTreeView1_ContextMenuOpening;

        this.radTreeView1.TreeViewElement.AllowEdit = true;
        this.radTreeView1.TreeViewElement.AllowAdd = true;
        this.radTreeView1.TreeViewElement.AllowRemove = true;
    }

    private void RadTreeView1_ContextMenuOpening(object sender, TreeViewContextMenuOpeningEventArgs e)
    {
        TreeViewDefaultContextMenu treeMenu = e.Menu as TreeViewDefaultContextMenu;
        treeMenu.Items.Remove(treeMenu.AddMenuItem);

        RadMenuItem item = new RadMenuItem("&New");

        item.Click -= Item_Click;
        item.Click += Item_Click;
        treeMenu.Items.Insert(2, item);
    }

    private void Item_Click(object sender, EventArgs e)
    {
        RadTreeNode parent = this.radTreeView1.SelectedNode;
        if (parent == null || parent.DataBoundItem == null)
        {
            return;
        }

        this.id++;
        BindingList<TreeViewDataObject> data = this.radTreeView1.DataSource as BindingList<TreeViewDataObject>;
        TreeViewDataObject newObject = new TreeViewDataObject()
        {
            Id = this.id,
            ParentId = ((TreeViewDataObject)parent.DataBoundItem).Id,
            Name = "New Name"
        };

        parent.Expanded = true;
        data.Add(newObject);
    }
}

public class TreeViewDataObject
{
    public int Id { get; set; }

    public int ParentId { get; set; }

    public string Name { get; set; }
}

To reproduce: add several nodes at design time in order to obtain a vertical scrollbar. Enable the drag and drop functionality by setting the AllowDragDrop property to true. If you start dragging you will notice that the RadTreeView doesn't auto-scroll  when you drag close to the borders of the visible area. 

Workaround: 

    Class CustomDragDropService
        Inherits TreeViewDragDropService

        Public Sub New(ByVal owner As RadTreeViewElement)
            MyBase.New(owner)
        End Sub

        Protected Overrides Sub SetHintWindowPosition(ByVal mousePt As Point)
        End Sub
    End Class

    Class CustomTreeViewElement
        Inherits RadTreeViewElement

        Protected Overrides ReadOnly Property ThemeEffectiveType As Type
            Get
                Return GetType(RadTreeViewElement)
            End Get
        End Property

        Protected Overrides Function CreateDragDropService() As TreeViewDragDropService
            Return New CustomDragDropService(Me)
        End Function
    End Class

    Class CustomTreeView
        Inherits RadTreeView

        Protected Overrides Function CreateTreeViewElement() As RadTreeViewElement
            Return New CustomTreeViewElement()
        End Function

        Public Overrides Property ThemeClassName As String
            Get
                Return GetType(RadTreeView).FullName
            End Get
            Set(value As String)
                MyBase.ThemeClassName = value
            End Set
        End Property
    End Class

To reproduce.
- Add 100 nodes so the scroll appears. 
- Try scrolling to bottom.

Workaround:
radTreeView1.TreeViewElement.Scroller.ScrollMode = ItemScrollerScrollModes.Discrete;

Workaround: Expand and collapse the nodes so that they are synchronized
this.radTreeView1.ExpandAll();
this.radTreeView1.CollapseAll();

To reproduce: use the following code snippet. You will notice that mnemonics are displayed.

        public RadForm1()
        {
            InitializeComponent();
            new RadControlSpyForm().Show();

            this.radTreeView1.DisplayMember = "name";
            this.radTreeView1.ParentMember = "pid";
            this.radTreeView1.ChildMember = "id";
            this.radTreeView1.DataSource = this.GetSampleData();
           
            this.radTreeView1.NodeFormatting += radTreeView1_NodeFormatting;
            this.radTreeView1.SelectedNodeChanged += radTreeView1_SelectedNodeChanged;
            
            this.radBreadCrumb1.DefaultTreeView = this.radTreeView1;
        }

        private void radTreeView1_SelectedNodeChanged(object sender, Telerik.WinControls.UI.RadTreeViewEventArgs e)
        {
            foreach (RadSplitButtonElement item in this.radBreadCrumb1.BreadCrumbElement.Items)
            {
                item.ActionButton.TextElement.UseMnemonic = false;
            }
        }
         
        private void radTreeView1_NodeFormatting(object sender, Telerik.WinControls.UI.TreeNodeFormattingEventArgs e)
        {
            e.NodeElement.ContentElement.UseMnemonic = false; 
        }

        private DataTable GetSampleData()
        {
            DataTable dt = new DataTable();

            DataColumn dc = new DataColumn();
            dc.ColumnName = "id";
            dc.DataType = typeof(int);
            dt.Columns.Add(dc);

            DataColumn dc1 = new DataColumn();
            dc1.ColumnName = "name";
            dc1.DataType = typeof(string);
            dt.Columns.Add(dc1);

            DataColumn dc2 = new DataColumn();
            dc2.ColumnName = "pid";
            dc2.DataType = typeof(int);
            dt.Columns.Add(dc2);

            DataRow dr = dt.NewRow();
            dr[0] = 0;
            dr[1] = "Hello & Goodbye";
            dr[2] = DBNull.Value;
            dt.Rows.Add(dr);

            dr = dt.NewRow();
            dr[0] = 1;
            dr[1] = @"&C:\";
            dr[2] = 0;
            dt.Rows.Add(dr);

            dr = dt.NewRow();
            dr[0] = 2;
            dr[1] = @"&D:\";
            dr[2] = 0;
            dt.Rows.Add(dr);

            dr = dt.NewRow();
            dr[0] = 3;
            dr[1] = "&Program Files";
            dr[2] = 1;
            dt.Rows.Add(dr);

            dr = dt.NewRow();
            dr[0] = 4;
            dr[1] = "M&icrosoft";
            dr[2] = 3;
            dt.Rows.Add(dr);

            dr = dt.NewRow();
            dr[0] = 5;
            dr[1] = "&Telerik";
            dr[2] = 3;
            dt.Rows.Add(dr);

            dr = dt.NewRow();
            dr[0] = 6;
            dr[1] = "&WINDOWS";
            dr[2] = 1;
            dt.Rows.Add(dr);

            return dt;
        }

Workaround: set the DefaultTreeView before subscribing to the treeview events.

            this.radBreadCrumb1.DefaultTreeView = this.radTreeView1;
            this.radTreeView1.NodeFormatting += radTreeView1_NodeFormatting;
            this.radTreeView1.SelectedNodeChanged += radTreeView1_SelectedNodeChanged;

I've got a tree with multiple nodes like

document1

 -page 1 

  -page 2

document1

 -page 1 

  -page 2

  -page 3

...

document10

 -page 1 

  -page 2

Due to the size of the treeview, only 2 or 3 documents are on screen, the rest is scrolled. (manually added items, no dynamic or lazy loading)

Lets say I click page 2 of document one, hold the mouse button to select more and go down to the last document (the tree is automatically scrolled down, as expected)

But when I go back to review what I selected, only the last items on screen are selected (documents 9 and 10 for example).

When I try to do the same selection with the arrow keys and the shift key, it works fine, but not with the mouse.

Greetings,

While testing the exporting feature of RadTreeView, I noticed the following issue :

Using the code below , everything works just fine :

But, the following line of the code raises an error in a specific circumasntance (I describe it more, further in the thread)   :

Error Screenshot is attached : 1.jpg

Details about the error :

The Specific Circumstance :

In my RadTreeView's NodeMouseClick , I add some child nodes to the node which is clicked, at runtime :

Then I found out that setting "exporter.ExportChildNodesGrouped" to True causes the error. But if it is set to false, no error raised even in the above Circumstance.

P.S  Normally setting "exporter.ExportChildNodesGrouped" to True or False doesn't cause any error, but adding some child nodes at run time surly does.

Thanks for your attention.

Sub New()

        InitializeComponent()
        Me.RadTreeView1.Nodes.Clear()
        Me.RadTreeView1.CheckBoxes = True

        Dim node = New RadTreeNode("1") With {.CheckType = CheckType.CheckBox, .Checked = True, .CheckState = ToggleState.Indeterminate}
        RadTreeView1.Nodes.Add(node)
        node.Nodes.Add(New RadTreeNode("1.1") With {.CheckType = CheckType.RadioButton, .Checked = True, .CheckState = ToggleState.Indeterminate})
        node.Nodes.Add(New RadTreeNode("1.2") With {.CheckType = CheckType.RadioButton})
        node.Nodes.Add(New RadTreeNode("1.3") With {.CheckType = CheckType.RadioButton})
        node = New RadTreeNode("2") With {.CheckType = CheckType.CheckBox, .Checked = True, .CheckState = ToggleState.Indeterminate}
        RadTreeView1.Nodes.Add(node)
        RadTreeView1.Nodes.Add(New RadTreeNode("3"))

    End Sub

Workaround:

    End Sub

Add a CodedUI test which records expanding a node in RadTreeView. Run the CodedUI test and you will see that the TestMethod throws the following exception:

"Microsoft.VisualStudio.TestTools.Extension.UITestControlNotFoundException: The playback failed to find the control with given search properties."

Add a RadTreeView and fill it with nodes so that a vertical scrollbar is shown.

The RadTreeView.TopNode property indicates that it is expected to return the RadTreeNode which visual node element is the first visible one in the current view. But it always return the first data node in RadTreeView no matter which node is currently visible at the top. This is because it consider the RadTreeNode.Visible property. 

Workaround:

            TreeNodeElement neFirstVisible = this.radTreeView1.TreeViewElement.ViewElement.Children[0] as TreeNodeElement;
            RadMessageBox.Show("TopNode = " + neFirstVisible.Data.Text);

How to reproduce:

    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;

Code snippet for reproducing the problem:

    Private Sub RadForm1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Me.SongsTableAdapter.Fill(Me.MusicCollectionDataSet.Songs)
        Me.ArtistsTableAdapter.Fill(Me.MusicCollectionDataSet.Artists)
        Me.AlbumsTableAdapter.Fill(Me.MusicCollectionDataSet.Albums)

        AddHandler Me.RadTreeView1.NodeDataBound, AddressOf RadTreeView1_NodeDataBound

        Me.RadTreeView1.DataSource = Me.ArtistsBindingSource
        Me.RadTreeView1.DisplayMember = "ArtistName"
        Me.RadTreeView1.ValueMember = "ArtistID"
        Me.RadTreeView1.RelationBindings.Add(New RelationBinding(Me.AlbumsBindingSource, "AlbumName", "ArtistID", "ArtistID", "AlbumID"))
        Me.RadTreeView1.RelationBindings.Add(New RelationBinding(Me.SongsBindingSource, "SongName", "AlbumID", "AlbumID", "SongID"))
        Me.RadTreeView1.CheckBoxes = True
        Me.RadTreeView1.AutoCheckChildNodes = True
        Me.RadTreeView1.TriStateMode = True
        Me.RadTreeView1.ExpandAll()
    End Sub

    Private Sub RadTreeView1_NodeDataBound(sender As Object, e As RadTreeViewEventArgs)
        If e.Node.Level = 0 Then
            e.Node.CheckType = CheckType.None
        Else
            e.Node.CheckType = CheckType.CheckBox
        End If
    End Sub

Workaround: instead of using the NodeDataBound  event, use the NodeFormatting event to hide the checkboxes for the desired nodes:

    Private Sub RadTreeView1_NodeFormatting(sender As Object, e As TreeNodeFormattingEventArgs)
        If e.Node.Level = 0 Then
            e.NodeElement.ToggleElement.Visibility = Telerik.WinControls.ElementVisibility.Collapsed
        Else
            e.NodeElement.ToggleElement.Visibility = Telerik.WinControls.ElementVisibility.Visible
        End If
    End Sub

Steps to reproduce:

1. Set SortOrder to Ascending

2. Rename a root node

I am using RadTreeView and setting FullRowSelect = false. This works for Windows7 them but doesn't work for Fluent theme.

1. Open Telerik Theme Viewer

2. Choose "Item Containers"

3. Observe "Tree"

4. Choose Theme "Office2019Dark"

Expected: Tree still shows content

Actual: Elements are not visible

Please use the attached sample project.

Result in 2021.1.326:

Result in 2021.2.511

If the list separator for the culture is ";"

and you have nodes in RadTreeView that are bold, the following XML will be serialized:

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>";

However, if you try to load this layout on another machine where the list separator is "," the nodes wouldn't be bold:

Expected:

Actual: