Export (0) Print
Expand All

DataKey.Value Property

Gets the value of the key field at index 0 in the DataKey object.

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

public virtual Object Value { get; }

Property Value

Type: System.Object
The value of the key field at index 0 in the DataKey.

Instead of using the Item or the Values property to retrieve a key field value from a DataKey object, you can use the Value property as a shortcut to determine the value of the key field at index 0 in the DataKey object. This property is commonly used to determine the key field value of a record when the record has only one key field.

NoteNote

If the DataKey object does not contain any key fields, null is returned.

The following code example demonstrates how to use the Value property to determine the primary key value of a record.


<%@ 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 CustomerDetailsView_DataBound(Object sender, EventArgs e)
  {
    // Get the DataKey object for the current record.
    DataKey key = CustomerDetailsView.DataKey;

    // Display the the value of the key field.
    MessageLabel.Text = "The key field value for the displayed record is " + 
      key.Value.ToString() + ".";
  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >

  <head runat="server">
    <title>DataKey Example</title>
</head>
<body>
    <form id="form1" runat="server">

      <h3>DataKey Example</h3>

        <asp:detailsview id="CustomerDetailsView"
          datasourceid="DetailsViewSource"
          autogeneraterows="true"
          datakeynames="CustomerID"  
          allowpaging="true"
          ondatabound="CustomerDetailsView_DataBound" 
          runat="server">

        </asp:detailsview>

        <br/>

        <asp:label id="MessageLabel"
          forecolor="Red"
          runat="server"/>

        <!-- This example uses Microsoft SQL Server and connects  -->
        <!-- to the Northwind sample database. Use an ASP.NET     -->
        <!-- expression to retrieve the connection string value   -->
        <!-- from the Web.config file.                            -->
        <asp:sqldatasource id="DetailsViewSource"
          selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
          connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
          runat="server"/>

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

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0
Show:
© 2015 Microsoft