DataKeyArray.Item[Int32] Property
Definition
Important
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Gets the DataKey object from the collection at the specified index.
public:
property System::Web::UI::WebControls::DataKey ^ default[int] { System::Web::UI::WebControls::DataKey ^ get(int index); };
public System.Web.UI.WebControls.DataKey this[int index] { get; }
member this.Item(int) : System.Web.UI.WebControls.DataKey
Default Public ReadOnly Property Item(index As Integer) As DataKey
Parameters
Property Value
The DataKey at the specified index in the collection.
Examples
The following code example demonstrates how to use the indexer to retrieve a DataKey object from a DataKeyArray collection.
<%@ 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 CustomerGridView_DataBound(Object sender, EventArgs e)
{
// Use the indexer to retrieve the DataKey object for the
// first record.
DataKey key = CustomerGridView.DataKeys[0];
// Display the value of the primary key for the first
// record displayed in the GridView control.
MessageLabel.Text = "The primary key of the first record displayed is " +
key.Value.ToString() + ".";
}
void CopyArray_Click(Object sender, EventArgs e)
{
DataKeyArray theKeys = CustomerGridView.DataKeys;
DataKey[] myNewArray = new DataKey[theKeys.Count];
theKeys.CopyTo(myNewArray, 0);
Label2.Visible = true;
// Display first page key values from the new array.
for (int i = 0; i < myNewArray.Length; i++)
{
Label2.Text += "<br />" + myNewArray[i].Value;
}
}
</script>
<html >
<head id="Head1" runat="server">
<title>DataKeyArray Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DataKeyArray Example</h3>
<asp:gridview id="CustomerGridView"
datasourceid="CustomerDataSource"
autogeneratecolumns="true"
datakeynames="CustomerID"
allowpaging="true"
ondatabound="CustomerGridView_DataBound"
runat="server">
</asp:gridview>
<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="CustomerDataSource"
selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
connectionstring="<%$ ConnectionStrings:NorthwindConnectionString %>"
runat="server"/>
<asp:Button ID="CopyArray"
runat="server"
Text="Copy DataKeyArray to Array"
OnClick="CopyArray_Click" />
<br />
<asp:label id="Label2"
runat="server"
Visible="false"
Text="First page of Copied Array Key Values" />
</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 CustomerGridView_DataBound(ByVal sender As Object, ByVal e As EventArgs) Handles CustomerGridView.DataBound
' Use the indexer to retrieve the DataKey object for the
' first record.
Dim key As DataKey = CustomerGridView.DataKeys(0)
' Display the value of the primary key for the first
' record displayed in the GridView control.
MessageLabel.Text = "The primary key of the first record displayed is " & _
key.Value.ToString() & "."
End Sub
Sub CopyArray_Click(ByVal sender As Object, ByVal e As EventArgs)
Dim theKeys As DataKeyArray = CustomerGridView.DataKeys
Dim myNewArray(theKeys.Count - 1) As DataKey
theKeys.CopyTo(myNewArray, 0)
Label2.Visible = True
' Display first page key values from the new array.
For i As Integer = 0 To myNewArray.Length - 1
Label2.Text &= "<br />" & myNewArray(i).Value
Next i
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>DataKeyArray Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DataKeyArray Example</h3>
<asp:gridview id="CustomerGridView"
datasourceid="CustomerDataSource"
autogeneratecolumns="true"
datakeynames="CustomerID"
allowpaging="true"
runat="server">
</asp:gridview>
<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="CustomerDataSource"
selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server"/>
<asp:Button ID="CopyArray"
runat="server"
Text="Copy DataKeyArray to Array"
OnClick="CopyArray_Click" />
<br />
<asp:label id="Label2"
runat="server"
Visible="false"
Text="First page of Copied Array Key Values" />
</form>
</body>
</html>
Remarks
Use this indexer to retrieve a DataKey object from the collection at the specified index, using array notation. This property is read-only.
Applies to
See also
Vertu í samstarfi við okkur á GitHub
Heimildina fyrir þetta efni er að finna á GitHub, þar sem þú getur líka búið til og farið yfir vandamál og sameinað beiðnir. Frekari upplýsingar er að finna í framlagshandbók okkar.