DataKeyArray.Item[Int32] Eigenschap
Definitie
Belangrijk
Bepaalde informatie heeft betrekking op een voorlopige productversie die aanzienlijk kan worden gewijzigd voordat deze wordt uitgebracht. Microsoft biedt geen enkele expliciete of impliciete garanties met betrekking tot de informatie die hier wordt verstrekt.
Hiermee haalt u het DataKey object op uit de verzameling op de opgegeven 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.DataKeyDefault Public ReadOnly Property Item(index As Integer) As DataKeyParameters
Waarde van eigenschap
De DataKey op de opgegeven index in de verzameling.
Voorbeelden
In het volgende codevoorbeeld ziet u hoe u de indexeerfunctie gebruikt om een DataKey object op te halen uit een DataKeyArray verzameling.
<%@ 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>
Opmerkingen
Gebruik deze indexeerfunctie om een DataKey object op te halen uit de verzameling in de opgegeven index, met behulp van matrix-notatie. Deze eigenschap is alleen-lezen.
