DataKey.Value Property
Definition
Important
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Gets the value of the key field at index 0 in the DataKey object.
public:
virtual property System::Object ^ Value { System::Object ^ get(); };
public virtual object Value { get; }
member this.Value : obj
Public Overridable ReadOnly Property Value As Object
Property Value
The value of the key field at index 0 in the DataKey.
Examples
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 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>
<%@ Page language="VB" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
Sub CustomerDetailsView_DataBound(ByVal sender As Object, ByVal e As EventArgs) Handles CustomerDetailsView.DataBound
' Get the DataKey object for the current record.
Dim key As DataKey = CustomerDetailsView.DataKey
' Display the value of the key field.
MessageLabel.Text = "The key field value for the displayed record is " & _
key.Value.ToString() & "."
End Sub
</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"
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>
Remarks
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.
Note
If the DataKey object does not contain any key fields, null
is returned.
Applies to
See also
.NET
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