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TreeNodeCollection.Add Method

Appends the specified TreeNode object to the end of the TreeNodeCollection object.

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

public void Add(
	TreeNode child
)

Parameters

child
Type: System.Web.UI.WebControls.TreeNode

The TreeNode object to append.

Use the Add method to append the specified TreeNode object to the end of the TreeNodeCollection.

NoteNote:

The TreeNodeCollection allows you to add null references (Nothing in Visual Basic), as well as duplicate TreeNode objects.

As an alternative, you can insert a TreeNode object in the TreeNodeCollection at a specific index by using the AddAt method.

The following example demonstrates how to use the Add method to programmatically add a node to the TreeNodeCollection. Notice that the Nodes and ChildNodes properties each return a TreeNodeCollection object.

<%@ 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_Load(Object sender, EventArgs e)
  {

    if (!IsPostBack)
    {

      // Use the Add and Remove methods to programmatically  
      // remove the Appendix C node and replace it with a new  
      // node. 
      LinksTreeView.Nodes.Remove(LinksTreeView.Nodes[3]);
      LinksTreeView.Nodes.Add(new TreeNode("New Appendix C"));

      // Use the AddAt and RemoveAt methods to programmatically  
      // remove the Chapter One node and replace it with a new node.
      LinksTreeView.Nodes[0].ChildNodes.RemoveAt(0);
      LinksTreeView.Nodes[0].ChildNodes.AddAt(0, new TreeNode("New Chapter One"));

      // Use the Clear method to remove all the child nodes of the  
      // Chapter Two node.
      LinksTreeView.Nodes[0].ChildNodes[1].ChildNodes.Clear();

    }

  }

</script>

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

      <h3>TreeNodeCollection Example</h3>

      <asp:TreeView id="LinksTreeView"
        Font-Names= "Arial"
        ForeColor="Blue"
        runat="server">

        <LevelStyles>

          <asp:TreeNodeStyle ChildNodesPadding="10" 
            Font-Bold="true" 
            Font-Size="12pt" 
            ForeColor="DarkGreen"/>
          <asp:TreeNodeStyle ChildNodesPadding="5" 
            Font-Bold="true" 
            Font-Size="10pt"/>
          <asp:TreeNodeStyle ChildNodesPadding="5" 
            Font-UnderLine="true" 
            Font-Size="10pt"/>
          <asp:TreeNodeStyle ChildNodesPadding="10" 
            Font-Size="8pt"/>

        </LevelStyles>

        <Nodes>

          <asp:TreeNode Text="Table of Contents"
            Expanded="true">

            <asp:TreeNode Text="Chapter One">

              <asp:TreeNode Text="Section 1.0">

                <asp:TreeNode Text="Topic 1.0.1"/>
                <asp:TreeNode Text="Topic 1.0.2"/>
                <asp:TreeNode Text="Topic 1.0.3"/>

              </asp:TreeNode>

              <asp:TreeNode Text="Section 1.1">

                <asp:TreeNode Text="Topic 1.1.1"/>
                <asp:TreeNode Text="Topic 1.1.2"/>
                <asp:TreeNode Text="Topic 1.1.3"/>
                <asp:TreeNode Text="Topic 1.1.4"/>

              </asp:TreeNode>

            </asp:TreeNode>

            <asp:TreeNode Text="Chapter Two">

              <asp:TreeNode Text="Section 2.0">

                <asp:TreeNode Text="Topic 2.0.1"/>
                <asp:TreeNode Text="Topic 2.0.2"/>

              </asp:TreeNode>

            </asp:TreeNode>

          </asp:TreeNode>

          <asp:TreeNode Text="Appendix A" />
          <asp:TreeNode Text="Appendix B" />
          <asp:TreeNode Text="Appendix C" />

        </Nodes>

      </asp:TreeView>

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

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

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

.NET Framework

Supported in: 3.5, 3.0, 2.0
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