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TreeNode Constructor

Initializes a new instance of the TreeNode class without text or a value.

Namespace:  System.Web.UI.WebControls
Assembly:  System.Web (in System.Web.dll)
public TreeNode()

Use this constructor to initialize a new instance of the TreeNode class using the default values.

NoteNote

When this constructor is used, all properties in the TreeNode object are set to their default values. Be sure to set the properties, as necessary, after creating the object.

The following code example demonstrates how to use this constructor to dynamically add a node to the TreeView control.


<%@ Page Language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  void Page_Init(Object sender, EventArgs e)
  {

    if(!IsPostBack)
    {

      // Add the first tree to the TreeView control.
      CreateTree("Section 1");

      // Add the second tree to the TreeView control.
      CreateTree("Section 2");

    }

  }

  void CreateTree(String NodeText)
  {

    // Create the root node using the default constructor.
    TreeNode root = new TreeNode();
    root.Text = NodeText;

    // Use the ChildNodes property of the root TreeNode to add child nodes.
    // Create the node using the constructor that takes the text parameter.
    root.ChildNodes.Add(new TreeNode("Topic 1"));

    // Create the node using the constructor that takes the text and value parameters.
    root.ChildNodes.Add(new TreeNode("Topic 2", "Value 2"));

    // Create the node using the constructor that takes the text, value, 
    // and imageUrl parameters.
    root.ChildNodes.Add(new TreeNode("Topic 3", "Value 3", "Image1.jpg"));

    // Create the node using the constructor that takes the text, value, 
    // imageUrl, navigateUrl, and target parameters.
    root.ChildNodes.Add(new TreeNode("Topic 4", "Value 4", "Image1.jpg", "http://www.microsoft.com", "_blank"));

    // Add the root node to the Nodes collection of the TreeView control.
    DynamicTreeView.Nodes.Add(root);

  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>TreeNode Constructor Example</title>
</head>
<body>
    <form id="form1" runat="server">

      <h3>TreeNode Constructor Example</h3>

      <asp:TreeView id="DynamicTreeView"
         EnableClientScript="false"
         ExpandDepth="2" 
         runat="server">

      </asp:TreeView>

    </form>
  </body>
</html>

.NET Framework

Supported in: 4.5.1, 4.5, 4, 3.5, 3.0, 2.0

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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