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Adding new nodes to RadTreeView with Ajax requests from the client

Updated on Oct 24, 2025

Environment

Product

RadTreeView for ASP.NET AJAX

Description

Find out two ways of adding new nodes to RadTreeView on a button click with an Ajax request with the help of RadAjaxManager and RadAjaxPanel in the Solution section below:

Solution

Scenario 1: RadAjaxManager and ajaxRequest:

ASPX

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>RadAjaxManager and ajaxRequest</title>
</head>

<body>
    <script type="text/javascript">
        function refreshWindow() {
            $find("<%= RadAjaxManager1.ClientID %>").ajaxRequest();
        }
    </script>

    <form id="form1" runat="server">
        <telerik:RadScriptManager ID="RadScriptManager1" runat="server"></telerik:RadScriptManager>

        <telerik:RadAjaxManager ID="RadAjaxManager1" runat="server">
            <AjaxSettings>
                <telerik:AjaxSetting AjaxControlID="RadAjaxManager1">
                    <UpdatedControls>
                        <telerik:AjaxUpdatedControl ControlID="RadButton1" />
                        <telerik:AjaxUpdatedControl ControlID="treeEmployees" />
                    </UpdatedControls>
                </telerik:AjaxSetting>
                <telerik:AjaxSetting AjaxControlID="RadButton1">
                    <UpdatedControls>
                        <telerik:AjaxUpdatedControl ControlID="treeEmployees" />
                    </UpdatedControls>
                </telerik:AjaxSetting>
            </AjaxSettings>
        </telerik:RadAjaxManager>

        <div style="height: 200px; width: 300px;">
            <telerik:RadTreeView ID="treeEmployees" runat="server" ShowLineImages="False" Skin="Glow" ForeColor="Black">
            </telerik:RadTreeView>
        </div>

        <telerik:RadButton ID="RadButton1" runat="server" Text="Add a new Treeview Node" AutoPostBack="false" OnClientClicked="refreshWindow"></telerik:RadButton>
    </form>
</body>
</html>

C#
using Telerik.Web.UI;

partial class testForm : System.Web.UI.Page
{
    protected void RadAjaxManager1_AjaxRequest(object sender, AjaxRequestEventArgs e)
    {
        RadTreeNode mainNode;

        mainNode = new RadTreeNode();
        mainNode.Text = "Testing";

        treeEmployees.Nodes.Add(mainNode);
    }
}
VB
Imports Telerik.Web.UI

Partial Class testForm
    Inherits System.Web.UI.Page


    Protected Sub RadAjaxManager1_AjaxRequest(sender As Object, e As AjaxRequestEventArgs) Handles RadAjaxManager1.AjaxRequest
        Dim mainNode As RadTreeNode

        mainNode = New RadTreeNode
        mainNode.Text = "Testing"

        treeEmployees.Nodes.Add(mainNode)
    End Sub

End Class

Scenario 2: RadAjaxPanel and ajaxRequest:

ASPX

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>

<body>
    <script type="text/javascript">

        function refreshWindow() {
            $find("<%= RadAjaxPanel1.ClientID %>").ajaxRequest();
        }
    </script>

    <form id="form1" runat="server">
        <telerik:RadScriptManager ID="RadScriptManager1" runat="server"></telerik:RadScriptManager>

        <div>
            <telerik:RadAjaxPanel ID="RadAjaxPanel1" runat="server" Height="200px" Width="300px" OnAjaxRequest="RadAjaxPanel1_AjaxRequest">
                <telerik:RadTreeView ID="treeEmployees" runat="server" ShowLineImages="False" Skin="Glow" ForeColor="Black">
                </telerik:RadTreeView>
            </telerik:RadAjaxPanel>

            <telerik:RadButton ID="RadButton1" runat="server" Text="Add a new Treeview Node" AutoPostBack="false" OnClientClicked="refreshWindow"></telerik:RadButton>
        </div>
    </form>
</body>
</html>

C#
using Telerik.Web.UI;

partial class testForm : System.Web.UI.Page
{
    protected void RadAjaxPanel1_AjaxRequest(object sender, AjaxRequestEventArgs e)
    {
        RadTreeNode mainNode;

        mainNode = new RadTreeNode();
        mainNode.Text = "Testing";

        treeEmployees.Nodes.Add(mainNode);
    }
}
VB
Imports Telerik.Web.UI

Partial Class testForm
    Inherits System.Web.UI.Page

    Protected Sub RadAjaxPanel1_AjaxRequest(sender As Object, e As AjaxRequestEventArgs)
        Dim mainNode As RadTreeNode

        mainNode = New RadTreeNode
        mainNode.Text = "Testing"

        treeEmployees.Nodes.Add(mainNode)
    End Sub
End Class