TreeView.TreeNodeDataBound Event

Occurs when a data item is bound to a node in the TreeView control.

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

public event TreeNodeEventHandler TreeNodeDataBound
<asp:TreeView OnTreeNodeDataBound="TreeNodeEventHandler" />

The TreeNodeDataBound event is raised when a data item is bound to a node in the TreeView control. This allows you to provide an event-handling method that performs a custom routine whenever this event occurs.

For more information about handling events, see Consuming Events.

This section contains two code examples. The first code example demonstrates how to use the TreeNodeDataBound event to change the image for a node when some condition is met. The second code example provides sample XML data for the first code example.

The following code example demonstrates how to use the TreeNodeDataBound event to change the image for a node when some condition is met. For this example to work correctly, you must copy the sample XML data, provided after this code example, to a file named Book.xml. Also be sure to provide your own images for this example to display.



<%@ 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 Data_Bound(Object sender, TreeNodeEventArgs e)
  {

    // Give the Chapter 2 node a custom image. 
    if(e.Node.Text == "Chapter 2")
    {
      e.Node.ImageUrl="Custom.jpg";
    }

  }

</script>

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

      <h3>TreeView TreeNodeDataBound Example</h3>

      <asp:TreeView id="BookTreeView" 
        DataSourceID="BookXmlDataSource"
        LeafNodeStyle-ImageUrl="Leaf.jpg"
        ParentNodeStyle-ImageUrl="Parent.jpg"
        RootNodeStyle-ImageUrl="Root.jpg"   
        OnTreeNodeDataBound="Data_Bound"
        runat="server">

        <DataBindings>
          <asp:TreeNodeBinding DataMember="Book" TextField="Title"/>
          <asp:TreeNodeBinding DataMember="Chapter" TextField="Heading"/>
          <asp:TreeNodeBinding DataMember="Section" TextField="Heading"/>
        </DataBindings>

      </asp:TreeView>

      <asp:XmlDataSource id="BookXmlDataSource"  
        DataFile="Book.xml"
        runat="server">
      </asp:XmlDataSource>

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



The following code example provides sample XML data for the preceding code example.

<Book Title="Book Title">
    <Chapter Heading="Chapter 1">
        <Section Heading="Section 1">
        </Section>
        <Section Heading="Section 2">
        </Section>
    </Chapter>
    <Chapter Heading="Chapter 2">
        <Section Heading="Section 1">
        </Section>
    </Chapter>
</Book>

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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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