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TreeNodeBinding.ImageUrl Property

Gets or sets the URL to an image that is displayed next to a node to which the TreeNodeBinding object is applied.

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

public string ImageUrl { get; set; }

Property Value

Type: System.String
The URL to an image that is displayed next to a node to which the TreeNodeBinding object is applied. The
ImageUrl property is not set.

When the TreeView control is bound to a data source, use the ImageUrl property to specify a custom image to bind to the ImageUrl property of a TreeNode object. This binding relationship affects all TreeNode objects to which the TreeNodeBinding object is applied. The image is displayed next to a node and can be in any file format (.jpg, .gif, .bmp, and so on), as long as the client browser supports that format.

NoteNote

You can override the image for an individual node by setting its ImageUrl property directly.

Instead of using this property to bind the same image to each node, you can bind the ImageUrl property of a TreeNode object to a field of a data source by setting the ImageUrlField property.

When displaying an image next to a node with the ImageUrl property, you should also consider setting the ImageToolTip property. The ToolTip text that you specify provides Assistive Technology devices with a description of the image that can be used to make the control more accessible.

The value of this property is stored in view state.

This section contains two code examples. The first code example demonstrates how to use the Depth property to apply a TreeNodeBinding object at a specific node depth. The second code example provides sample XML data for the first code example.

The following code example demonstrates how to use the ImageUrl property to specify a custom image for a node to which the TreeNodeBinding object is applied. For this example to work correctly, you must copy the sample XML data, provided after this code example, to a file named Booklist.xml.


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

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>TreeViewBinding Example</title>
</head>
<body>
    <form id="form1" runat="server">

      <h3>TreeViewBinding Example</h3>

      <!-- Set the Text, ImageUrl, ImageToolTip, -->
      <!-- NavigateUrl, Value, and ToolTip       -->
      <!-- properties of a TreeNodeBinding       -->
      <!-- object declaratively.                 -->   
      <asp:TreeView id="BookTreeView" 
        DataSourceID="BookXmlDataSource"
        Target="_blank" 
        runat="server">

        <DataBindings>
          <asp:TreeNodeBinding DataMember="Books" 
            Depth="0" 
            TextField="Text"/>
          <asp:TreeNodeBinding DataMember="Book" 
            Depth="1" 
            Text="Book Title" 
            ImageUrl="Image.jpg"
            ImageToolTip="Book Image" 
            NavigateUrl="http://www.microsoft.com" 
            Value="BookID" 
            ToolTip="Book Information"/>
          <asp:TreeNodeBinding DataMember="Description" 
            Depth="2" 
            TextField="Text"/>
          <asp:TreeNodeBinding DataMember="Price" 
            Depth="2" 
            TextField="Value"/>
        </DataBindings>

      </asp:TreeView>

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

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

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

<Books Text="Books List">
    <Book Text="Book Title One"
        Value="1" 
        Image="Bookimage1.jpg"
        ImageToolTip="Book 1 Photo" 
        Nav="http://www.microsoft.com"
        Tip="Book Title 1">
        <Description Text="Book Description">
        </Description>
        <Price Value="$1.99">
        </Price>
        <Author Text="Author Name"
            Value="LastName" 
            Image="Authorimage1.jpg" 
            Nav="http://www.microsoft.com"
            Tip="Author Name">
        </Author>
    </Book>
    <Book Text="Book Title Two"
        Value="2" 
        Image="Bookimage2.jpg"
        ImageToolTip="Book 2 Photo" 
        Nav="http://www.microsoft.com"
        Tip="Click Me">
        <Description Text="Book Description">
        </Description>
        <Price Value="$2.99">
        </Price>
        <Author Text="Author Name"
            Value="LastName" 
            Image="Authorimage2.jpg" 
            Nav="http://www.microsoft.com"
            Tip="Author Name">
        </Author>
    </Book>
</Books>

.NET Framework

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

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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