TreeNodeCollection.AddAt Method (Int32, TreeNode)
Inserts the specified TreeNode object in a TreeNodeCollection object at the specified index location.
Assembly: System.Web (in System.Web.dll)
Parameters
- index
-
Type:
System.Int32
The zero-based index location at which to insert the TreeNode object.
- child
-
Type:
System.Web.UI.WebControls.TreeNode
The TreeNode object to add.
| Exception | Condition |
|---|---|
| ArgumentNullException | child is null. |
Use the AddAt method to insert the specified TreeNode object in the TreeNodeCollection at the specified zero-based index.
Note |
|---|
The TreeNodeCollection allows you to insert null references (Nothing in Visual Basic), as well as duplicate TreeNode objects. |
As an alternative, you can append a TreeNode object to the end of the TreeNodeCollection by using the Add method.
The following example demonstrates how to use the AddAt method to programmatically add a node to the TreeNodeCollection. Notice that the Nodes and ChildNodes properties each return a TreeNodeCollection object.
<%@ Page Language="VB" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="server"> Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) If Not IsPostBack Then ' 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() End If End Sub </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>
Available since 2.0
