TreeNodeBinding.Value Property

 
System_CAPS_noteNote

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Gets or sets a displayed value that is not displayed but is used to store any additional data about a node to which the TreeNodeBinding object is applied, such as data used for handling postback events.

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

public string Value { get; set; }

Property Value

Type: System.String

Supplemental data about a node to which the TreeNodeBinding object is applied; this data is not displayed. The default is an empty string ("").

When the TreeView control is bound to a data source, use the Value property to specify the value to bind to the Value property of a TreeNode object. This binding relationship affects all TreeNode objects to which the TreeNodeBinding object is applied. The Value property is used to supplement the Text property by storing any additional data associated with the node to which the TreeNodeBinding object is applied. This value is not displayed in the control and is commonly used to store data for handling postback events.

System_CAPS_noteNote

You can selectively override the Value property by setting the Value property of each node directly.

Instead of using the Value property to bind the same value to each node, you can bind the Value property of a TreeNode object to a field of a data source by setting the ValueField property.

The value of this property is stored in view state.

The value of this property, when set, can be saved automatically to a resource file by using a designer tool. For more information, see LocalizableAttribute and ASP.NET Globalization and Localization.

This section contains two code examples. The first code example demonstrates how to use the Value property to store supplemental data about a node to which the TreeNodeBinding object is applied. The second code example provides sample XML data for the first code example.

The following example demonstrates how to use the Value property to store supplemental data about 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 code 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
Available since 2.0
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