TreeNodeDataBound Event
Collapse the table of content
Expand the table of content

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

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 NIB: 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
Available since 2.0
Return to top
Show:
© 2016 Microsoft