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How to arrange elements in a custom RadTreeView node


Product Version Product Author
2023.1.314 RadTreeView for WinForms Dinko Krastev


By design, RadTreeView allows customizing the visual node elements. The Custom Nodes help article demonstrates a step-by-step tutorial on how to use a custom TreeNodeElement. However, a common scenario is to use several elements in a custom node. In this example, we will demonstrate how to arrange elements in a custom node in a way that changing the width of the control will change only the text part while the rest elements will stay static.

treeview-custom-node-arrangeoverride 001


For the purpose of this article, we will populate the RadTreeView with sample data. In the code snippet, you can observe that we need to subscribe to the CreateNodeElement event. In the event handler, you can replace the default node element with a custom one.

public partial class Form1 : Form
    BindingList<TreeItem> treeItems = new BindingList<TreeItem>();
    Random rnd = new Random();
    public Form1()
        this.radTreeView1.ItemHeight = 40;
        this.radTreeView1.ShowLines = true;
        this.radTreeView1.TreeIndent = 32;
        for (int i = 0; i < 4; i++)
            treeItems.Add(new TreeItem() { Id = i, Name = "Lorem Ipsum is simply dummy text of the printing and typesetting industry.", Price= rnd.Next(1000000,5000000) });
        this.radTreeView1.DataSource = treeItems;
        this.radTreeView1.CreateNodeElement += RadTreeView1_CreateNodeElement;

    private void RadTreeView1_CreateNodeElement(object sender, Telerik.WinControls.UI.CreateTreeNodeElementEventArgs e)
        e.NodeElement = new CustomTreeNodeElement();
public class TreeItem
    public int Id { get; set; }
    public string Name { get; set; }
    public decimal Price { get; set; }


Public Partial Class Form1
    Inherits Form

    Private treeItems As BindingList(Of TreeItem) = New BindingList(Of TreeItem)()
    Private rnd As Random = New Random()

    Public Sub New()
        Me.radTreeView1.ItemHeight = 40
        Me.radTreeView1.ShowLines = True
        Me.radTreeView1.TreeIndent = 32

        For i As Integer = 0 To 4 - 1
            treeItems.Add(New TreeItem() With {
                .Id = i,
                .Name = "Lorem Ipsum is simply dummy text of the printing and typesetting industry.",
                .Price = rnd.[Next](1000000, 5000000)

        Me.radTreeView1.DataSource = treeItems
        AddHandler Me.radTreeView1.CreateNodeElement, AddressOf RadTreeView1_CreateNodeElement
    End Sub

    Private Sub RadTreeView1_CreateNodeElement(ByVal sender As Object, ByVal e As Telerik.WinControls.UI.CreateTreeNodeElementEventArgs)
        e.NodeElement = New CustomTreeNodeElement()
    End Sub
End Class

Public Class TreeItem
    Public Property Id As Integer
    Public Property Name As String
    Public Property Price As Decimal
End Class

Now we need to create our custom node. We will add different types of elements inside the custom node. Each element will represent data related to the current node. In our case, only the nameElement TextPrimitive part will depend on its parent node width, while the rest of the elements will not overlap each other and stay static. An important step here is to set TextWrap and AutoEllipsis properties of the TextPrimitive__. To arrange the elements correctly you need to override the ArrangeOverride method of the CustomContentElement. In the method, you can calculate the width of all elements except the text part element. The width of the TextPrimitive element will be the remaining space left from the whole node width, without the width of the other elements.

public class CustomTreeNodeElement : TreeNodeElement
    protected override Type ThemeEffectiveType
            return typeof(TreeNodeElement);
    protected override TreeNodeContentElement CreateContentElement()
        return new CustomContentElement();

public class CustomContentElement : TreeNodeContentElement
    LightVisualElement numberElement;
    TextPrimitive nameElement;
    ImagePrimitive saveStatusImage;
    ImagePrimitive errorImage;
    ImagePrimitive timeImage;
    TextPrimitive priceText;
    RadDropDownButtonElement detailsButton;
    public override void Synchronize()
        TreeNodeElement treeNodeElement = this.NodeElement;
        RadTreeNode node = treeNodeElement.Data;
        TreeItem dataItem = (TreeItem)node.DataBoundItem;
        numberElement.Text = dataItem.Id + "";
        nameElement.Text = dataItem.Name;
        priceText.Text = dataItem.Price + "";

    protected override void CreateChildElements()
        this.StretchHorizontally = true;

        this.numberElement = new LightVisualElement();

        this.nameElement = new TextPrimitive()
            TextWrap = true,
            AutoEllipsis = true,

        this.saveStatusImage = new ImagePrimitive()
            Image = Resources.save_as1,

        this.errorImage = new ImagePrimitive()
            Image = Resources.error,

        this.timeImage = new ImagePrimitive()
            Image = Resources.Alarm,

        this.priceText = new TextPrimitive();

        this.detailsButton = new RadDropDownButtonElement()
            Text = "...",
            ShowArrow = false

    protected override SizeF ArrangeOverride(SizeF finalSize)
        var availableSize = base.ArrangeOverride(finalSize);
        var width = this.numberElement.DesiredSize.Width + this.saveStatusImage.DesiredSize.Width + this.errorImage.DesiredSize.Width + this.timeImage.DesiredSize.Width + this.priceText.DesiredSize.Width + this.detailsButton.DesiredSize.Width;

        if (width < availableSize.Width)
            PointF topLeftCorner = new PointF(0, 0);
            this.numberElement.Arrange(new RectangleF(topLeftCorner, numberElement.DesiredSize));
            topLeftCorner = new PointF(topLeftCorner.X + this.numberElement.DesiredSize.Width, 0);

            var nameWidth = availableSize.Width - width;
            nameElement.Arrange(new RectangleF(topLeftCorner, new SizeF(nameWidth, nameElement.DesiredSize.Height)));
            topLeftCorner = new PointF(topLeftCorner.X + nameWidth, 0);

            saveStatusImage.Arrange(new RectangleF(topLeftCorner, saveStatusImage.DesiredSize));
            topLeftCorner = new PointF(topLeftCorner.X + this.saveStatusImage.DesiredSize.Width, 0);

            errorImage.Arrange(new RectangleF(topLeftCorner, errorImage.DesiredSize));
            topLeftCorner = new PointF(topLeftCorner.X + this.errorImage.DesiredSize.Width, 0);

            timeImage.Arrange(new RectangleF(topLeftCorner, timeImage.DesiredSize));
            topLeftCorner = new PointF(topLeftCorner.X + this.timeImage.DesiredSize.Width, 0);

            priceText.Arrange(new RectangleF(topLeftCorner, priceText.DesiredSize));
            topLeftCorner = new PointF(topLeftCorner.X + this.priceText.DesiredSize.Width, 0);

            detailsButton.Arrange(new RectangleF(topLeftCorner, detailsButton.DesiredSize));

        return availableSize;
    protected override Type ThemeEffectiveType
            return typeof(TreeNodeContentElement);

Public Class CustomTreeNodeElement
    Inherits TreeNodeElement

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

    Protected Overrides Function CreateContentElement() As TreeNodeContentElement
        Return New CustomContentElement()
    End Function
End Class

Public Class CustomContentElement
    Inherits TreeNodeContentElement

    Private numberElement As LightVisualElement
    Private nameElement As TextPrimitive
    Private saveStatusImage As ImagePrimitive
    Private errorImage As ImagePrimitive
    Private timeImage As ImagePrimitive
    Private priceText As TextPrimitive
    Private detailsButton As RadDropDownButtonElement

    Public Overrides Sub Synchronize()
        Dim treeNodeElement As TreeNodeElement = Me.NodeElement
        Dim node As RadTreeNode = treeNodeElement.Data
        Dim dataItem As TreeItem = CType(node.DataBoundItem, TreeItem)
        numberElement.Text = dataItem.Id & ""
        nameElement.Text = dataItem.Name
        priceText.Text = dataItem.Price & ""
    End Sub

    Protected Overrides Sub CreateChildElements()
        Me.StretchHorizontally = True
        Me.numberElement = New LightVisualElement()
        Me.nameElement = New TextPrimitive() With {
            .TextWrap = True,
            .AutoEllipsis = True
        Me.saveStatusImage = New ImagePrimitive() With {
            .Image = Resources.save_as1
        Me.errorImage = New ImagePrimitive() With {
            .Image = Resources.[error]
        Me.timeImage = New ImagePrimitive() With {
            .Image = Resources.Alarm
        Me.priceText = New TextPrimitive()
        Me.detailsButton = New RadDropDownButtonElement() With {
            .Text = "...",
            .ShowArrow = False
    End Sub

    Protected Overrides Function ArrangeOverride(ByVal finalSize As SizeF) As SizeF
        Dim availableSize = MyBase.ArrangeOverride(finalSize)
        Dim width = Me.numberElement.DesiredSize.Width + Me.saveStatusImage.DesiredSize.Width + Me.errorImage.DesiredSize.Width + Me.timeImage.DesiredSize.Width + Me.priceText.DesiredSize.Width + Me.detailsButton.DesiredSize.Width

        If width < availableSize.Width Then
            Dim topLeftCorner As PointF = New PointF(0, 0)
            Me.numberElement.Arrange(New RectangleF(topLeftCorner, numberElement.DesiredSize))
            topLeftCorner = New PointF(topLeftCorner.X + Me.numberElement.DesiredSize.Width, 0)
            Dim nameWidth = availableSize.Width - width
            nameElement.Arrange(New RectangleF(topLeftCorner, New SizeF(nameWidth, nameElement.DesiredSize.Height)))
            topLeftCorner = New PointF(topLeftCorner.X + nameWidth, 0)
            saveStatusImage.Arrange(New RectangleF(topLeftCorner, saveStatusImage.DesiredSize))
            topLeftCorner = New PointF(topLeftCorner.X + Me.saveStatusImage.DesiredSize.Width, 0)
            errorImage.Arrange(New RectangleF(topLeftCorner, errorImage.DesiredSize))
            topLeftCorner = New PointF(topLeftCorner.X + Me.errorImage.DesiredSize.Width, 0)
            timeImage.Arrange(New RectangleF(topLeftCorner, timeImage.DesiredSize))
            topLeftCorner = New PointF(topLeftCorner.X + Me.timeImage.DesiredSize.Width, 0)
            priceText.Arrange(New RectangleF(topLeftCorner, priceText.DesiredSize))
            topLeftCorner = New PointF(topLeftCorner.X + Me.priceText.DesiredSize.Width, 0)
            detailsButton.Arrange(New RectangleF(topLeftCorner, detailsButton.DesiredSize))
        End If

        Return availableSize
    End Function

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

See Also

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