Verwenden des ASP.NET UpdatePanel-Steuerelements mit datengebundenen Steuerelementen
Aktualisiert: November 2007
Sie können in Ihren AJAX-fähigen ASP.NET-Anwendungen durch Teilrendering der Seiten eine verbesserte Benutzerfreundlichkeit erreichen. Durch Teilrendering einer Seite muss als Reaktion auf ein Postback nicht mehr die gesamte Seite aktualisiert werden. Stattdessen können Sie den Bereich der Seite angeben, der aktualisiert werden soll. Dadurch müssen Benutzer bei einem Postback nicht mehr auf das erneute Laden der gesamten Seite warten.
In diesem Thema wird davon ausgegangen, dass Sie mit dem UpdatePanel-Steuerelement vertraut sind. Andernfalls sollten Sie sich mit den folgenden Themen befassen:
Sie können das Teilrendering von Seiten aktivieren, indem Sie das UpdatePanel-Webserversteuerelement und das ScriptManager-Webserversteuerelement verwenden. Das UpdatePanel-Steuerelement identifiziert den Bereich einer Seite, der aktualisiert werden kann. Das ScriptManager-Steuerelement überwacht die UpdatePanel-Steuerelemente, die sich auf einer Seite befinden, sowie die Steuerelemente, die eine Aktualisierung der UpdatePanel-Steuerelemente auslösen. Die Steuerelemente innerhalb eines UpdatePanel-Steuerelements, die ein Postback verursachen, werden automatisch als Trigger für das UpdatePanel identifiziert. Außerdem können Sie Steuerelemente angeben, die sich außerhalb eines UpdatePanel-Steuerelements befinden. Externe Trigger können untergeordnete Steuerelemente eines anderen UpdatePanel-Steuerelements sein. Weitere Informationen finden Sie unter Übersicht über das Teilrendering von Seiten und Übersicht über das UpdatePanel-Steuerelement.
Dieses Thema enthält folgende Abschnitte:
Verwenden von mehreren UpdatePanel-Steuerelementen auf einer Seite
Deaktivieren von automatischen Triggern
Verwalten von Triggern und programmgesteuertes Aktualisieren eines UpdatePanels
Aktivieren des Teilrenderings von Seiten in einem benutzerdefinierten Steuerelement
Verwenden von mehreren UpdatePanel-Steuerelementen auf einer Seite
Die Anzahl von UpdatePanel-Steuerelementen, die auf einer Seite enthalten sein können, ist nicht begrenzt. Hierdurch können Sie Bereiche auf einer Seite angeben, die unabhängig von der gesamten Seite und voneinander aktualisiert werden.
Die UpdateMode-Eigenschaft eines UpdatePanel-Steuerelements ist in der Standardeinstellung auf Always festgelegt. Dies bedeutet, dass das UpdatePanel-Steuerelement die Seite beim Auslösen einer Teilaktualisierung aktualisiert, auch wenn der Trigger nicht zu diesem UpdatePanel-Steuerelement gehört. Um sicherzustellen, dass das UpdatePanel-Steuerelement nur beim Auslösen eines zugehörigen Triggers aktualisiert wird, können Sie die UpdateMode-Eigenschaft des UpdatePanel-Steuerelements auf Conditional festlegen.
Im folgenden Beispiel sind zwei UpdatePanel-Steuerelemente enthalten. Ein Steuerelement enthält Websteuerelemente, die Benutzereingaben annehmen, und das andere Steuerelement zeigt die Eingaben des Benutzers an. Bei beiden UpdatePanel-Steuerelementen ist die UpdateMode-Eigenschaft auf Conditional festgelegt. Wenn ein Benutzer auf die Schaltfläche Abbrechen klickt, um die Felder des Eingabeformulars zu löschen, wird daher nur das Eingabeformular des UpdatePanel-Steuerelements aktualisiert. Wenn ein Benutzer auf die Schaltfläche Einfügen klickt, um das Formular zu übermitteln, werden beide UpdatePanel-Steuerelemente aktualisiert.
<%@ Page Language="VB" %>
<%@ Import Namespace="System.Collections.Generic" %>
<!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 id="Head1" >
<title>Enter New Employees</title>
<script >
Private EmployeeList As List(Of Employee)
Protected Sub Page_Load()
If Not IsPostBack Then
EmployeeList = New List(Of Employee)
EmployeeList.Add(New Employee(1, "Jump", "Dan"))
EmployeeList.Add(New Employee(2, "Kirwan", "Yvette"))
ViewState("EmployeeList") = EmployeeList
Else
EmployeeList = CType(ViewState("EmployeeList"), List(Of Employee))
End If
EmployeesGridView.DataSource = EmployeeList
EmployeesGridView.DataBind()
End Sub
Protected Sub InsertButton_Click(ByVal sender As Object, ByVal e As EventArgs)
If String.IsNullOrEmpty(FirstNameTextBox.Text) Or _
String.IsNullOrEmpty(LastNameTextBox.Text) Then Return
Dim employeeID As Integer = EmployeeList(EmployeeList.Count - 1).EmployeeID + 1
Dim lastName As String = Server.HtmlEncode(FirstNameTextBox.Text)
Dim firstName As String = Server.HtmlEncode(LastNameTextBox.Text)
FirstNameTextBox.Text = String.Empty
LastNameTextBox.Text = String.Empty
EmployeeList.Add(New Employee(employeeID, lastName, firstName))
ViewState("EmployeeList") = EmployeeList
EmployeesGridView.DataBind()
EmployeesGridView.PageIndex = EmployeesGridView.PageCount
End Sub
Protected Sub CancelButton_Click(ByVal sender As Object, ByVal e As EventArgs)
FirstNameTextBox.Text = String.Empty
LastNameTextBox.Text = String.Empty
End Sub
<Serializable()> _
Public Class Employee
Private _employeeID As Integer
Private _lastName As String
Private _firstName As String
Public ReadOnly Property EmployeeID() As Integer
Get
Return _employeeID
End Get
End Property
Public ReadOnly Property LastName() As String
Get
Return _lastName
End Get
End Property
Public ReadOnly Property FirstName() As String
Get
Return _firstName
End Get
End Property
Public Sub New(ByVal employeeID As Integer, ByVal lastName As String, ByVal firstName As String)
_employeeID = employeeID
_lastName = lastName
_firstName = firstName
End Sub
End Class
</script>
</head>
<body>
<form id="form1" >
<div>
</div>
<asp:ScriptManager ID="ScriptManager1" EnablePartialRendering="true" />
<table>
<tr>
<td style="height: 206px" valign="top">
<asp:UpdatePanel ID="InsertEmployeeUpdatePanel" UpdateMode="Conditional">
<ContentTemplate>
<table cellpadding="2" border="0" style="background-color:#7C6F57">
<tr>
<td><asp:Label ID="FirstNameLabel" AssociatedControlID="FirstNameTextBox"
Text="First Name" ForeColor="White" /></td>
<td><asp:TextBox ID="FirstNameTextBox" /></td>
</tr>
<tr>
<td><asp:Label ID="LastNameLabel" AssociatedControlID="LastNameTextBox"
Text="Last Name" ForeColor="White" /></td>
<td><asp:TextBox ID="LastNameTextBox" /></td>
</tr>
<tr>
<td></td>
<td>
<asp:LinkButton ID="InsertButton" Text="Insert" OnClick="InsertButton_Click" ForeColor="White" />
<asp:LinkButton ID="Cancelbutton" Text="Cancel" OnClick="CancelButton_Click" ForeColor="White" />
</td>
</tr>
</table>
<asp:Label ID="InputTimeLabel"><%=DateTime.Now %></asp:Label>
</ContentTemplate>
</asp:UpdatePanel>
</td>
<td style="height: 206px" valign="top">
<asp:UpdatePanel ID="EmployeesUpdatePanel" UpdateMode="Conditional">
<ContentTemplate>
<asp:GridView ID="EmployeesGridView" BackColor="LightGoldenrodYellow" BorderColor="Tan"
BorderWidth="1px" CellPadding="2" ForeColor="Black" GridLines="None" AutoGenerateColumns="False">
<FooterStyle BackColor="Tan" />
<SelectedRowStyle BackColor="DarkSlateBlue" ForeColor="GhostWhite" />
<PagerStyle BackColor="PaleGoldenrod" ForeColor="DarkSlateBlue" HorizontalAlign="Center" />
<HeaderStyle BackColor="Tan" Font-Bold="True" />
<AlternatingRowStyle BackColor="PaleGoldenrod" />
<Columns>
<asp:BoundField DataField="EmployeeID" HeaderText="Employee ID" />
<asp:BoundField DataField="LastName" HeaderText="Last Name" />
<asp:BoundField DataField="FirstName" HeaderText="First Name" />
</Columns>
<PagerSettings PageButtonCount="5" />
</asp:GridView>
<asp:Label ID="ListTimeLabel"><%=DateTime.Now %></asp:Label>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="InsertButton" EventName="Click" />
</Triggers>
</asp:UpdatePanel>
</td>
</tr>
</table>
</form>
</body>
</html>
<%@ Page Language="C#" %>
<%@ Import Namespace="System.Collections.Generic" %>
<!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 >
<title>Enter New Employees</title>
<script >
private List<Employee> EmployeeList;
protected void Page_Load()
{
if (!IsPostBack)
{
EmployeeList = new List<Employee>();
EmployeeList.Add(new Employee(1, "Jump", "Dan"));
EmployeeList.Add(new Employee(2, "Kirwan", "Yvette"));
ViewState["EmployeeList"] = EmployeeList;
}
else
EmployeeList = (List<Employee>)ViewState["EmployeeList"];
EmployeesGridView.DataSource = EmployeeList;
EmployeesGridView.DataBind();
}
protected void InsertButton_Click(object sender, EventArgs e)
{
if (String.IsNullOrEmpty(FirstNameTextBox.Text) ||
String.IsNullOrEmpty(LastNameTextBox.Text)) { return; }
int employeeID = EmployeeList[EmployeeList.Count-1].EmployeeID + 1;
string lastName = Server.HtmlEncode(FirstNameTextBox.Text);
string firstName = Server.HtmlEncode(LastNameTextBox.Text);
FirstNameTextBox.Text = String.Empty;
LastNameTextBox.Text = String.Empty;
EmployeeList.Add(new Employee(employeeID, lastName, firstName));
ViewState["EmployeeList"] = EmployeeList;
EmployeesGridView.DataBind();
EmployeesGridView.PageIndex = EmployeesGridView.PageCount;
}
protected void CancelButton_Click(object sender, EventArgs e)
{
FirstNameTextBox.Text = String.Empty;
LastNameTextBox.Text = String.Empty;
}
[Serializable]
public class Employee
{
private int _employeeID;
private string _lastName;
private string _firstName;
public int EmployeeID
{
get { return _employeeID; }
}
public string LastName
{
get { return _lastName; }
}
public string FirstName
{
get { return _firstName; }
}
public Employee(int employeeID, string lastName, string firstName)
{
_employeeID = employeeID;
_lastName = lastName;
_firstName = firstName;
}
}
</script>
</head>
<body>
<form id="form1" >
<div>
</div>
<asp:ScriptManager ID="ScriptManager1" EnablePartialRendering="true" />
<table>
<tr>
<td style="height: 206px" valign="top">
<asp:UpdatePanel ID="InsertEmployeeUpdatePanel" UpdateMode="Conditional">
<ContentTemplate>
<table cellpadding="2" border="0" style="background-color:#7C6F57">
<tr>
<td><asp:Label ID="FirstNameLabel" AssociatedControlID="FirstNameTextBox"
Text="First Name" ForeColor="White" /></td>
<td><asp:TextBox ID="FirstNameTextBox" /></td>
</tr>
<tr>
<td><asp:Label ID="LastNameLabel" AssociatedControlID="LastNameTextBox"
Text="Last Name" ForeColor="White" /></td>
<td><asp:TextBox ID="LastNameTextBox" /></td>
</tr>
<tr>
<td></td>
<td>
<asp:LinkButton ID="InsertButton" Text="Insert" OnClick="InsertButton_Click" ForeColor="White" />
<asp:LinkButton ID="Cancelbutton" Text="Cancel" OnClick="CancelButton_Click" ForeColor="White" />
</td>
</tr>
</table>
<asp:Label ID="InputTimeLabel"><%=DateTime.Now %></asp:Label>
</ContentTemplate>
</asp:UpdatePanel>
</td>
<td style="height: 206px" valign="top">
<asp:UpdatePanel ID="EmployeesUpdatePanel" UpdateMode="Conditional">
<ContentTemplate>
<asp:GridView ID="EmployeesGridView" BackColor="LightGoldenrodYellow" BorderColor="Tan"
BorderWidth="1px" CellPadding="2" ForeColor="Black" GridLines="None" AutoGenerateColumns="False">
<FooterStyle BackColor="Tan" />
<SelectedRowStyle BackColor="DarkSlateBlue" ForeColor="GhostWhite" />
<PagerStyle BackColor="PaleGoldenrod" ForeColor="DarkSlateBlue" HorizontalAlign="Center" />
<HeaderStyle BackColor="Tan" Font-Bold="True" />
<AlternatingRowStyle BackColor="PaleGoldenrod" />
<Columns>
<asp:BoundField DataField="EmployeeID" HeaderText="Employee ID" />
<asp:BoundField DataField="LastName" HeaderText="Last Name" />
<asp:BoundField DataField="FirstName" HeaderText="First Name" />
</Columns>
<PagerSettings PageButtonCount="5" />
</asp:GridView>
<asp:Label ID="ListTimeLabel"><%=DateTime.Now %></asp:Label>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="InsertButton" EventName="Click" />
</Triggers>
</asp:UpdatePanel>
</td>
</tr>
</table>
</form>
</body>
</html>
Sie können ein UpdatePanel-Steuerelement auch in ein anderes UpdatePanel-Steuerelement schachteln. Wenn Sie die UpdateMode-Eigenschaft des äußeren und des geschachtelten Steuerelements auf Conditional festlegen, wird der äußere Bereich beim Auslösen eines Triggers für den inneren Bereich nicht aktualisiert. Wenn jedoch der äußere Bereich aufgrund eines Triggers aktualisiert wird, werden sowohl der äußere als auch der innere Bereich aktualisiert.
Das folgende Beispiel enthält ein GridView-Steuerelement, das sich innerhalb eines UpdatePanel-Steuerelements befindet. Jede Zeile des GridView-Steuerelements enthält ein geschachteltes GridView-Steuerelement, das sich innerhalb eines untergeordneten UpdatePanel-Steuerelements befindet. Wenn von einem inneren GridView-Steuerelement eine neue Seite mit Datensätzen angefordert wird, werden die Seitenbereiche des äußeren Bereichs und die Bereiche in den anderen Zeilen des äußeren GridView-Steuerelements nicht aktualisiert. Wenn das äußere GridView-Steuerelement eine neue Seite mit Datensätzen anzeigt, werden alle Seitenbereiche des äußeren Bereichs und der geschachtelten Bereiche aktualisiert.
<%@ Page Language="VB" %>
<!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 >
<title>Browse Departments</title>
<script >
Protected Sub DepartmentsGridView_RowDataBound(sender As object, e As GridViewRowEventArgs)
If e.Row.RowType = DataControlRowType.DataRow Then
Dim s As SqlDataSource = CType(e.Row.FindControl("EmployeesDataSource"), SqlDataSource)
Dim r As System.Data.DataRowView = CType(e.Row.DataItem, System.Data.DataRowView)
s.SelectParameters("DepartmentID").DefaultValue = r("DepartmentID").ToString()
End If
End Sub
</script>
</head>
<body>
<form id="form1" >
<div>
<asp:ScriptManager ID="ScriptManager1" EnablePartialRendering="true" />
<asp:UpdatePanel ID="UpdatePanel2" UpdateMode="Conditional">
<ContentTemplate>
<asp:GridView ID="DepartmentsGridView" AllowPaging="True" AllowSorting="True"
AutoGenerateColumns="False" CellPadding="4" DataSourceID="DepartmentDataSource"
ForeColor="#333333" GridLines="None" PageSize="3" OnRowDataBound="DepartmentsGridView_RowDataBound">
<FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
<Columns>
<asp:BoundField DataField="GroupName" HeaderText="Division" SortExpression="GroupName" >
<ItemStyle Width="200px" />
</asp:BoundField>
<asp:BoundField DataField="Name" HeaderText="Department Name" SortExpression="Name" >
<ItemStyle Width="160px" />
</asp:BoundField>
<asp:TemplateField HeaderText="Employees">
<ItemTemplate>
<asp:UpdatePanel ID="UpdatePanel1" UpdateMode="Conditional">
<ContentTemplate>
<asp:GridView ID="EmployeesGridView" AllowPaging="True" AllowSorting="True"
AutoGenerateColumns="False" BackColor="White" BorderColor="#999999" BorderStyle="None"
BorderWidth="1px" CellPadding="3" DataSourceID="EmployeesDataSource" GridLines="Vertical"
PageSize="4">
<FooterStyle BackColor="#CCCCCC" ForeColor="Black" />
<Columns>
<asp:BoundField DataField="FirstName" HeaderText="First Name" SortExpression="FirstName" >
<ItemStyle Width="80px" />
</asp:BoundField>
<asp:BoundField DataField="LastName" HeaderText="Last Name" SortExpression="LastName" >
<ItemStyle Width="160px" />
</asp:BoundField>
</Columns>
<RowStyle BackColor="#EEEEEE" ForeColor="Black" />
<SelectedRowStyle BackColor="#008A8C" Font-Bold="True" ForeColor="White" />
<PagerStyle BackColor="#999999" ForeColor="Black" HorizontalAlign="Center" />
<HeaderStyle BackColor="#000084" Font-Bold="True" ForeColor="White" />
<AlternatingRowStyle BackColor="Gainsboro" />
</asp:GridView>
<asp:Label ID="InnerTimeLabel"><%=DateTime.Now %></asp:Label>
<asp:SqlDataSource ID="EmployeesDataSource" ConnectionString="<%$ ConnectionStrings:AdventureWorksConnectionString %>"
SelectCommand="SELECT HumanResources.EmployeeDepartmentHistory.DepartmentID,
HumanResources.vEmployee.EmployeeID,
HumanResources.vEmployee.FirstName,
HumanResources.vEmployee.LastName
FROM HumanResources.EmployeeDepartmentHistory
INNER JOIN HumanResources.vEmployee
ON HumanResources.EmployeeDepartmentHistory.EmployeeID = HumanResources.vEmployee.EmployeeID
WHERE HumanResources.EmployeeDepartmentHistory.DepartmentID = @DepartmentID
ORDER BY HumanResources.vEmployee.LastName ASC, HumanResources.vEmployee.FirstName ASC">
<SelectParameters>
<asp:Parameter Name="DepartmentID" DefaultValue="0" Type="int32" />
</SelectParameters>
</asp:SqlDataSource>
</ContentTemplate>
</asp:UpdatePanel>
</ItemTemplate>
<ItemStyle Height="170px" Width="260px" />
</asp:TemplateField>
</Columns>
<RowStyle BackColor="#F7F6F3" ForeColor="#333333" VerticalAlign="Top" />
<EditRowStyle BackColor="#999999" />
<SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" />
<PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" />
<HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" HorizontalAlign="Left" />
<AlternatingRowStyle BackColor="White" ForeColor="#284775" VerticalAlign="Top" />
</asp:GridView>
<asp:Label ID="OuterTimeLabel"><%=DateTime.Now %></asp:Label>
</ContentTemplate>
</asp:UpdatePanel>
<asp:SqlDataSource ID="DepartmentDataSource" ConnectionString="<%$ ConnectionStrings:AdventureWorksConnectionString %>"
SelectCommand="SELECT DepartmentID, Name, GroupName FROM HumanResources.Department ORDER BY Name">
</asp:SqlDataSource>
</div>
</form>
</body>
</html>
<%@ 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 >
<title>Browse Departments</title>
<script >
protected void DepartmentsGridView_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
SqlDataSource s = (SqlDataSource)e.Row.FindControl("EmployeesDataSource");
System.Data.DataRowView r = (System.Data.DataRowView)e.Row.DataItem;
s.SelectParameters["DepartmentID"].DefaultValue = r["DepartmentID"].ToString();
}
}
</script>
</head>
<body>
<form id="form1" >
<div>
<asp:ScriptManager ID="ScriptManager1" EnablePartialRendering="true" />
<asp:UpdatePanel ID="UpdatePanel2" UpdateMode="Conditional">
<ContentTemplate>
<asp:GridView ID="DepartmentsGridView" AllowPaging="True" AllowSorting="True"
AutoGenerateColumns="False" CellPadding="4" DataSourceID="DepartmentDataSource"
ForeColor="#333333" GridLines="None" PageSize="3" OnRowDataBound="DepartmentsGridView_RowDataBound">
<FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
<Columns>
<asp:BoundField DataField="GroupName" HeaderText="Division" SortExpression="GroupName" >
<ItemStyle Width="200px" />
</asp:BoundField>
<asp:BoundField DataField="Name" HeaderText="Department Name" SortExpression="Name" >
<ItemStyle Width="160px" />
</asp:BoundField>
<asp:TemplateField HeaderText="Employees">
<ItemTemplate>
<asp:UpdatePanel ID="UpdatePanel1" UpdateMode="Conditional">
<ContentTemplate>
<asp:GridView ID="EmployeesGridView" AllowPaging="True" AllowSorting="True"
AutoGenerateColumns="False" BackColor="White" BorderColor="#999999" BorderStyle="None"
BorderWidth="1px" CellPadding="3" DataSourceID="EmployeesDataSource" GridLines="Vertical"
PageSize="4">
<FooterStyle BackColor="#CCCCCC" ForeColor="Black" />
<Columns>
<asp:BoundField DataField="FirstName" HeaderText="First Name" SortExpression="FirstName" >
<ItemStyle Width="80px" />
</asp:BoundField>
<asp:BoundField DataField="LastName" HeaderText="Last Name" SortExpression="LastName" >
<ItemStyle Width="160px" />
</asp:BoundField>
</Columns>
<RowStyle BackColor="#EEEEEE" ForeColor="Black" />
<SelectedRowStyle BackColor="#008A8C" Font-Bold="True" ForeColor="White" />
<PagerStyle BackColor="#999999" ForeColor="Black" HorizontalAlign="Center" />
<HeaderStyle BackColor="#000084" Font-Bold="True" ForeColor="White" />
<AlternatingRowStyle BackColor="Gainsboro" />
</asp:GridView>
<asp:Label ID="InnerTimeLabel"><%=DateTime.Now %></asp:Label>
<asp:SqlDataSource ID="EmployeesDataSource" ConnectionString="<%$ ConnectionStrings:AdventureWorksConnectionString %>"
SelectCommand="SELECT HumanResources.EmployeeDepartmentHistory.DepartmentID,
HumanResources.vEmployee.EmployeeID,
HumanResources.vEmployee.FirstName,
HumanResources.vEmployee.LastName
FROM HumanResources.EmployeeDepartmentHistory
INNER JOIN HumanResources.vEmployee
ON HumanResources.EmployeeDepartmentHistory.EmployeeID = HumanResources.vEmployee.EmployeeID
WHERE HumanResources.EmployeeDepartmentHistory.DepartmentID = @DepartmentID
ORDER BY HumanResources.vEmployee.LastName ASC, HumanResources.vEmployee.FirstName ASC">
<SelectParameters>
<asp:Parameter Name="DepartmentID" DefaultValue="0" Type="int32" />
</SelectParameters>
</asp:SqlDataSource>
</ContentTemplate>
</asp:UpdatePanel>
</ItemTemplate>
<ItemStyle Height="170px" Width="260px" />
</asp:TemplateField>
</Columns>
<RowStyle BackColor="#F7F6F3" ForeColor="#333333" VerticalAlign="Top" />
<EditRowStyle BackColor="#999999" />
<SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" />
<PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" />
<HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" HorizontalAlign="Left" />
<AlternatingRowStyle BackColor="White" ForeColor="#284775" VerticalAlign="Top" />
</asp:GridView>
<asp:Label ID="OuterTimeLabel"><%=DateTime.Now %></asp:Label>
</ContentTemplate>
</asp:UpdatePanel>
<asp:SqlDataSource ID="DepartmentDataSource" ConnectionString="<%$ ConnectionStrings:AdventureWorksConnectionString %>"
SelectCommand="SELECT DepartmentID, Name, GroupName FROM HumanResources.Department ORDER BY Name">
</asp:SqlDataSource>
</div>
</form>
</body>
</html>
Deaktivieren von automatischen Triggern
Steuerelemente innerhalb eines UpdatePanel-Steuerelements, die einen Postback verursachen, sind automatisch als Trigger für dieses UpdatePanel-Steuerelement konfiguriert. Sie können die automatischen Trigger jedoch auch deaktivieren und die Aktualisierung des UpdatePanel-Steuerelements ausschließlich durch externe Steuerelemente auslösen. Legen Sie hierfür die ChildrenAsTriggers-Eigenschaft des UpdatePanel-Steuerelements auf false fest. Legen Sie anschließend die UpdateMode-Eigenschaft des UpdatePanel-Steuerelements auf Conditional fest. Bei diesen Eigenschafteneinstellungen wird der Bereich nur durch einen Trigger eines externen Steuerelements oder durch den Aufruf der Update-Methode aktualisiert.
Im folgenden Beispiel werden die Kategorien, Unterkategorien und Namen der Produkte aus der AdventureWorks-Beispieldatenbank angezeigt. Die Liste der Kategorien wird selten geändert und muss nicht jedes Mal aktualisiert werden, wenn eine Liste mit Unterkategorien oder Produkten angezeigt wird. Deshalb können Sie in dem UpdatePanel-Steuerelement, das die Kategorienliste enthält, die ChildrenAsTriggers-Eigenschaft auf false und die UpdateMode-Eigenschaft auf Conditional festlegen. Hierdurch wird sichergestellt, dass das UpdatePanel-Steuerelement nur auf explizite Anforderung aktualisiert wird.
<%@ Page Language="VB" AutoEventWireup="true" %>
<!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 >
<title>UpdatePanel Example</title>
<script >
Protected Sub ProductsUpdatePanel_Load(sender As Object, e As EventArgs)
CategoryTimeLabel.Text = DateTime.Now.ToString()
End Sub
Protected Sub CategoriesRepeater_ItemCommand(sender As Object, e As RepeaterCommandEventArgs)
SubcategoriesDataSource.SelectParameters("CategoryID").DefaultValue = e.CommandArgument.ToString()
SubcategoriesRepeater.DataBind()
ProductsDataSource.SelectParameters("SubcategoryID").DefaultValue = "0"
ProductsGridView.DataBind()
End Sub
Protected Sub SubcategoriesRepeater_ItemCommand(sender As Object, e As RepeaterCommandEventArgs)
ProductsDataSource.SelectParameters("SubcategoryID").DefaultValue = e.CommandArgument.ToString()
ProductsGridView.DataBind()
End Sub
Protected Sub RefreshCategoriesButton_Click(sender As Object, e As EventArgs)
SubcategoriesDataSource.SelectParameters("CategoryID").DefaultValue = "0"
SubcategoriesRepeater.DataBind()
ProductsDataSource.SelectParameters("SubcategoryID").DefaultValue = "0"
ProductsGridView.DataBind()
End Sub
</script>
</head>
<body>
<form id="form1" >
<div>
<asp:ScriptManager ID="ScriptManager1" >
</asp:ScriptManager>
<table>
<tr>
<td valign="top" style="width:120px">
<asp:UpdatePanel ID="ProductsUpdatePanel"
ChildrenAsTriggers="False"
OnLoad="ProductsUpdatePanel_Load" UpdateMode="Conditional">
<ContentTemplate>
<asp:Repeater ID="CategoryRepeater" DataSourceID="CategoriesDataSource"
OnItemCommand="CategoriesRepeater_ItemCommand">
<ItemTemplate>
<asp:LinkButton ID="SelectCategoryButton"
Text='<%# Eval("Name") %>'
CommandName="SelectCategory"
CommandArgument='<%#Eval("ProductCategoryID") %>' /><br />
</ItemTemplate>
</asp:Repeater>
<asp:SqlDataSource ID="CategoriesDataSource" ConnectionString="<%$ ConnectionStrings:AdventureWorksConnectionString %>"
SelectCommand="SELECT Name, ProductCategoryID FROM Production.ProductCategory ORDER BY ProductCategoryID">
</asp:SqlDataSource>
<br />
<asp:Label ID="CategoryTimeLabel" Text="Label" Font-Size="Smaller"></asp:Label>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="RefreshCategoriesButton" EventName="Click" />
</Triggers>
</asp:UpdatePanel>
<asp:LinkButton runat="Server" ID="RefreshCategoriesButton" Text="Refresh Category List"
OnClick="RefreshCategoriesButton_Click" Font-Size="smaller" />
</td>
<td valign="top">
<asp:UpdatePanel ID="SubcategoriesUpdatePanel" >
<ContentTemplate>
<asp:Repeater ID="SubcategoriesRepeater" DataSourceID="SubcategoriesDataSource"
OnItemCommand="SubcategoriesRepeater_ItemCommand" >
<ItemTemplate>
<asp:LinkButton ID="SelectSubcategoryButton"
Text='<%# Eval("Name") %>'
CommandName="SelectSubcategory"
CommandArgument='<%#Eval("ProductSubcategoryID") %>' /><br />
</ItemTemplate>
</asp:Repeater>
<asp:SqlDataSource ID="SubcategoriesDataSource" ConnectionString="<%$ ConnectionStrings:AdventureWorksConnectionString %>"
SelectCommand="SELECT Name, ProductSubcategoryID FROM Production.ProductSubcategory
WHERE Production.ProductSubcategory.ProductCategoryID = @CategoryID
ORDER BY Name">
<SelectParameters>
<asp:Parameter Name="CategoryID" DefaultValue="0" />
</SelectParameters>
</asp:SqlDataSource>
</ContentTemplate>
</asp:UpdatePanel>
</td>
<td valign="top">
<asp:UpdatePanel ID="ProductUpdatePanel" >
<ContentTemplate>
<asp:GridView ID="ProductsGridView" AllowPaging="True" AutoGenerateColumns="False" BackColor="White" BorderColor="#E7E7FF" BorderStyle="None" BorderWidth="1px" CellPadding="3" DataKeyNames="ProductID" DataSourceID="ProductsDataSource" GridLines="Horizontal">
<FooterStyle BackColor="#B5C7DE" ForeColor="#4A3C8C" />
<Columns>
<asp:BoundField DataField="Name" HeaderText="Name" SortExpression="Name" >
<ItemStyle Width="240px" />
</asp:BoundField>
</Columns>
<RowStyle BackColor="#E7E7FF" ForeColor="#4A3C8C" />
<SelectedRowStyle BackColor="#738A9C" Font-Bold="True" ForeColor="#F7F7F7" />
<PagerStyle BackColor="#E7E7FF" ForeColor="#4A3C8C" HorizontalAlign="Right" />
<HeaderStyle BackColor="#4A3C8C" Font-Bold="True" ForeColor="#F7F7F7" />
<AlternatingRowStyle BackColor="#F7F7F7" />
</asp:GridView>
<asp:SqlDataSource ID="ProductsDataSource" ConnectionString="<%$ ConnectionStrings:AdventureWorksConnectionString %>"
SelectCommand="SELECT ProductID, Name, ProductSubcategoryID FROM Production.Product WHERE (ProductSubcategoryID = @SubcategoryID) ORDER BY Name">
<SelectParameters>
<asp:Parameter DefaultValue="0" Name="SubcategoryID" />
</SelectParameters>
</asp:SqlDataSource>
</ContentTemplate>
</asp:UpdatePanel>
</td>
</tr>
</table>
</div>
</form>
</body>
</html>
<%@ Page Language="C#" AutoEventWireup="true" %>
<!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 >
<title>UpdatePanel Example</title>
<script >
protected void ProductsUpdatePanel_Load(object sender, EventArgs e)
{
CategoryTimeLabel.Text = DateTime.Now.ToString();
}
protected void CategoriesRepeater_ItemCommand(object sender, RepeaterCommandEventArgs e)
{
SubcategoriesDataSource.SelectParameters["CategoryID"].DefaultValue = e.CommandArgument.ToString();
SubcategoriesRepeater.DataBind();
ProductsDataSource.SelectParameters["SubcategoryID"].DefaultValue = "0";
ProductsGridView.DataBind();
}
protected void SubcategoriesRepeater_ItemCommand(object sender, RepeaterCommandEventArgs e)
{
ProductsDataSource.SelectParameters["SubcategoryID"].DefaultValue = e.CommandArgument.ToString();
ProductsGridView.DataBind();
}
protected void RefreshCategoriesButton_Click(object sender, EventArgs e)
{
SubcategoriesDataSource.SelectParameters["CategoryID"].DefaultValue = "0";
SubcategoriesRepeater.DataBind();
ProductsDataSource.SelectParameters["SubcategoryID"].DefaultValue = "0";
ProductsGridView.DataBind();
}
</script>
</head>
<body>
<form id="form1" >
<div>
<asp:ScriptManager ID="ScriptManager1" >
</asp:ScriptManager>
<table>
<tr>
<td valign="top" style="width:120px">
<asp:UpdatePanel ID="ProductsUpdatePanel"
ChildrenAsTriggers="False"
OnLoad="ProductsUpdatePanel_Load" UpdateMode="Conditional">
<ContentTemplate>
<asp:Repeater ID="CategoryRepeater" DataSourceID="CategoriesDataSource"
OnItemCommand="CategoriesRepeater_ItemCommand">
<ItemTemplate>
<asp:LinkButton ID="SelectCategoryButton"
Text='<%# Eval("Name") %>'
CommandName="SelectCategory"
CommandArgument='<%#Eval("ProductCategoryID") %>' /><br />
</ItemTemplate>
</asp:Repeater>
<asp:SqlDataSource ID="CategoriesDataSource" ConnectionString="<%$ ConnectionStrings:AdventureWorksConnectionString %>"
SelectCommand="SELECT Name, ProductCategoryID FROM Production.ProductCategory ORDER BY ProductCategoryID">
</asp:SqlDataSource>
<br />
<asp:Label ID="CategoryTimeLabel" Text="Label" Font-Size="Smaller"></asp:Label>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="RefreshCategoriesButton" EventName="Click" />
</Triggers>
</asp:UpdatePanel>
<asp:LinkButton runat="Server" ID="RefreshCategoriesButton" Text="Refresh Category List"
OnClick="RefreshCategoriesButton_Click" Font-Size="smaller" />
</td>
<td valign="top">
<asp:UpdatePanel ID="SubcategoriesUpdatePanel" >
<ContentTemplate>
<asp:Repeater ID="SubcategoriesRepeater" DataSourceID="SubcategoriesDataSource"
OnItemCommand="SubcategoriesRepeater_ItemCommand" >
<ItemTemplate>
<asp:LinkButton ID="SelectSubcategoryButton"
Text='<%# Eval("Name") %>'
CommandName="SelectSubcategory"
CommandArgument='<%#Eval("ProductSubcategoryID") %>' /><br />
</ItemTemplate>
</asp:Repeater>
<asp:SqlDataSource ID="SubcategoriesDataSource" ConnectionString="<%$ ConnectionStrings:AdventureWorksConnectionString %>"
SelectCommand="SELECT Name, ProductSubcategoryID FROM Production.ProductSubcategory
WHERE Production.ProductSubcategory.ProductCategoryID = @CategoryID
ORDER BY Name">
<SelectParameters>
<asp:Parameter Name="CategoryID" DefaultValue="0" />
</SelectParameters>
</asp:SqlDataSource>
</ContentTemplate>
</asp:UpdatePanel>
</td>
<td valign="top">
<asp:UpdatePanel ID="ProductUpdatePanel" >
<ContentTemplate>
<asp:GridView ID="ProductsGridView" AllowPaging="True" AutoGenerateColumns="False" BackColor="White" BorderColor="#E7E7FF" BorderStyle="None" BorderWidth="1px" CellPadding="3" DataKeyNames="ProductID" DataSourceID="ProductsDataSource" GridLines="Horizontal">
<FooterStyle BackColor="#B5C7DE" ForeColor="#4A3C8C" />
<Columns>
<asp:BoundField DataField="Name" HeaderText="Name" SortExpression="Name" >
<ItemStyle Width="240px" />
</asp:BoundField>
</Columns>
<RowStyle BackColor="#E7E7FF" ForeColor="#4A3C8C" />
<SelectedRowStyle BackColor="#738A9C" Font-Bold="True" ForeColor="#F7F7F7" />
<PagerStyle BackColor="#E7E7FF" ForeColor="#4A3C8C" HorizontalAlign="Right" />
<HeaderStyle BackColor="#4A3C8C" Font-Bold="True" ForeColor="#F7F7F7" />
<AlternatingRowStyle BackColor="#F7F7F7" />
</asp:GridView>
<asp:SqlDataSource ID="ProductsDataSource" ConnectionString="<%$ ConnectionStrings:AdventureWorksConnectionString %>"
SelectCommand="SELECT ProductID, Name, ProductSubcategoryID FROM Production.Product WHERE (ProductSubcategoryID = @SubcategoryID) ORDER BY Name">
<SelectParameters>
<asp:Parameter DefaultValue="0" Name="SubcategoryID" />
</SelectParameters>
</asp:SqlDataSource>
</ContentTemplate>
</asp:UpdatePanel>
</td>
</tr>
</table>
</div>
</form>
</body>
</html>
Verwalten von Triggern und programmgesteuertes Aktualisieren eines UpdatePanels
Steuerelemente, die eine Aktualisierung eines UpdatePanel-Steuerelements auslösen, müssen im ScriptManager-Steuerelement auf der Seite registriert werden. Für die untergeordneten Steuerelemente eines UpdatePanel-Steuerelements erfolgt dies automatisch. Sie können Trigger mithilfe der Triggers-Auflistung eines UpdatePanel-Steuerelements deklarativ angeben. Darüber hinaus können Sie Trigger programmgesteuert identifizieren und die Aktualisierung eines UpdatePanel-Steuerelements mit Servercode auslösen.
In Fällen, bei denen zur Entwurfszeit kein Triggersteuerelement verfügbar ist, können Sie das Steuerelement mit der RegisterAsyncPostBackControl-Methode des ScriptManager-Steuerelements als Trigger registrieren. Steuerelemente, die programmgesteuert als Trigger identifiziert werden, müssen bei jedem Postback registriert werden. Es wird empfohlen, dass Sie Aufrufe der RegisterAsyncPostBackControl-Methode in das Page_Load-Ereignis der Seite einfügen, wie im folgenden Beispiel dargestellt:
Protected Sub Page_Load()
ScriptManager1.RegisterAsyncPostBackControl(SurveyDataList)
End Sub
protected void Page_Load()
{
ScriptManager1.RegisterAsyncPostBackControl(SurveyDataList);
}
Um das UpdatePanel-Steuerelement programmgesteuert zu aktualisieren, können Sie die Update-Methode eines UpdatePanel-Steuerelements aufrufen. Dies ist hilfreich, wenn vor dem Aktualisieren des UpdatePanel-Steuerelements auf dem Server verschiedene Verarbeitungsschritte ausgeführt werden müssen. Im folgenden Beispiel ist dargestellt, wie ein UpdatePanel programmgesteuert aktualisiert wird.
Protected Sub ChoicesRadioButtonList_SelectedIndexChanged(sender As Object, e As EventArgs)
Dim answers As SortedList = Me.AnsweredQuestions
Dim r As RadioButtonList = CType(sender, RadioButtonList)
answers(r.ToolTip) = r.SelectedValue
Me.AnsweredQuestions = answers
ResultsList.DataSource = Me.AnsweredQuestions
ResultsList.DataBind()
If Me.AnsweredQuestions.Count = SurveyDataList.Items.Count Then _
SubmitButton.Visible = True
UpdatePanel1.Update()
End Sub
protected void ChoicesRadioButtonList_SelectedIndexChanged(object sender, EventArgs e)
{
SortedList answers = this.AnsweredQuestions;
RadioButtonList r = (RadioButtonList)sender;
answers[r.ToolTip] = r.SelectedValue;
this.AnsweredQuestions = answers;
ResultsList.DataSource = this.AnsweredQuestions;
ResultsList.DataBind();
if (this.AnsweredQuestions.Count == SurveyDataList.Items.Count)
SubmitButton.Visible = true;
UpdatePanel1.Update();
}
Im folgenden Beispiel wird eine Seite dargestellt, auf der ein Steuerelement mithilfe der RegisterAsyncPostBackControl-Methode als Trigger registriert wird. Anschließend wird ein UpdatePanel-Steuerelement mit der Update-Methode programmgesteuert aktualisiert.
<%@ Page Language="VB" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script >
Protected Property AnsweredQuestions As SortedList
Get
If ViewState("AnsweredQuestions") IsNot Nothing Then
Return CType(ViewState("AnsweredQuestions"), SortedList)
Else
Return New SortedList()
End If
End Get
Set
ViewState("AnsweredQuestions") = value
End Set
End Property
Protected Sub Page_Load()
ScriptManager1.RegisterAsyncPostBackControl(SurveyDataList)
End Sub
Protected Sub ChoicesRadioButtonList_SelectedIndexChanged(sender As Object, e As EventArgs)
Dim answers As SortedList = Me.AnsweredQuestions
Dim r As RadioButtonList = CType(sender, RadioButtonList)
answers(r.ToolTip) = r.SelectedValue
Me.AnsweredQuestions = answers
ResultsList.DataSource = Me.AnsweredQuestions
ResultsList.DataBind()
If Me.AnsweredQuestions.Count = SurveyDataList.Items.Count Then _
SubmitButton.Visible = True
UpdatePanel1.Update()
End Sub
Protected Sub SubmitButton_Click(sender As Object, e As EventArgs)
' Submit responses.
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" >
<title>Registering Controls as Async Postback Controls</title>
<style type="text/css">
.AnswerFloatPanelStyle {
background-color: bisque;
position: absolute;
right: 10px;
height: 130px;
width: 150px;
border-right: silver thin solid; border-top: silver thin solid;
border-left: silver thin solid; border-bottom: silver thin solid;
}
</style>
</head>
<body>
<form id="form1" >
<div>
<asp:ScriptManager ID="ScriptManager1" />
<div id="AnswerFloatPanel" class="AnswerFloatPanelStyle" >
<asp:UpdatePanel ID="UpdatePanel1" UpdateMode="Conditional" >
<ContentTemplate>
Completed Questions:
<asp:DataList ID="ResultsList" >
<ItemTemplate>
<asp:Label ID="ResultQuestion" Text='<%# Eval("Key") %>' />
::
<asp:Label ID="ResultAnswer" Text='<%# Eval("Value") %>' />
</ItemTemplate>
</asp:DataList>
<p style="text-align: right">
<asp:Button ID="SubmitButton" Text="Submit" Visible="false"
OnClick="SubmitButton_Click" />
</p>
<asp:Label ID="Message" runat="Server" />
</ContentTemplate>
</asp:UpdatePanel>
</div>
<asp:XmlDataSource ID="SurveyDataSource"
XPath="/Questions/Question"
DataFile="~/App_Data/SurveyQuestions.xml"/>
<asp:DataList
ID="SurveyDataList"
DataSourceID="SurveyDataSource"
>
<ItemTemplate>
<table cellpadding="2" cellspacing="2">
<tr>
<td valign="top">
<asp:Label id="QuestionLabel" Text='<%# XPath("@Title")%>' />
</td>
</tr>
<tr><td>
<asp:RadioButtonList ID="ChoicesRadioButtonList"
DataSource='<%#XPathSelect("Choices/Choice") %>'
DataTextField="InnerText" DataValueField="InnerText"
AutoPostBack="True"
ToolTip='<%# "Question" + XPath("@ID") %>'
OnSelectedIndexChanged="ChoicesRadioButtonList_SelectedIndexChanged"/>
</td></tr>
</table>
<hr />
</ItemTemplate>
</asp:DataList>
</div>
</form>
</body>
</html>
<%@ Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script >
protected SortedList AnsweredQuestions
{
get { return (SortedList)(ViewState["AnsweredQuestions"] ?? new SortedList()); }
set { ViewState["AnsweredQuestions"] = value; }
}
protected void Page_Load()
{
ScriptManager1.RegisterAsyncPostBackControl(SurveyDataList);
}
protected void ChoicesRadioButtonList_SelectedIndexChanged(object sender, EventArgs e)
{
SortedList answers = this.AnsweredQuestions;
RadioButtonList r = (RadioButtonList)sender;
answers[r.ToolTip] = r.SelectedValue;
this.AnsweredQuestions = answers;
ResultsList.DataSource = this.AnsweredQuestions;
ResultsList.DataBind();
if (this.AnsweredQuestions.Count == SurveyDataList.Items.Count)
SubmitButton.Visible = true;
UpdatePanel1.Update();
}
protected void SubmitButton_Click(object sender, EventArgs e)
{
// Submit responses.
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" >
<title>Registering Controls as Async Postback Controls</title>
<style type="text/css">
.AnswerFloatPanelStyle {
background-color: bisque;
position: absolute;
right: 10px;
height: 130px;
width: 150px;
border-right: silver thin solid; border-top: silver thin solid;
border-left: silver thin solid; border-bottom: silver thin solid;
}
</style>
</head>
<body>
<form id="form1" >
<div>
<asp:ScriptManager ID="ScriptManager1" />
<div id="AnswerFloatPanel" class="AnswerFloatPanelStyle" >
<asp:UpdatePanel ID="UpdatePanel1" UpdateMode="Conditional" >
<ContentTemplate>
Completed Questions:
<asp:DataList ID="ResultsList" >
<ItemTemplate>
<asp:Label ID="ResultQuestion" Text='<%# Eval("Key") %>' />
::
<asp:Label ID="ResultAnswer" Text='<%# Eval("Value") %>' />
</ItemTemplate>
</asp:DataList>
<p style="text-align: right">
<asp:Button ID="SubmitButton" Text="Submit" Visible="false"
OnClick="SubmitButton_Click" />
</p>
<asp:Label ID="Message" runat="Server" />
</ContentTemplate>
</asp:UpdatePanel>
</div>
<asp:XmlDataSource ID="SurveyDataSource"
XPath="/Questions/Question"
DataFile="~/App_Data/SurveyQuestions.xml"/>
<asp:DataList
ID="SurveyDataList"
DataSourceID="SurveyDataSource"
>
<ItemTemplate>
<table cellpadding="2" cellspacing="2">
<tr>
<td valign="top">
<asp:Label id="QuestionLabel" Text='<%# XPath("@Title")%>' />
</td>
</tr>
<tr><td>
<asp:RadioButtonList ID="ChoicesRadioButtonList"
DataSource='<%#XPathSelect("Choices/Choice") %>'
DataTextField="InnerText" DataValueField="InnerText"
AutoPostBack="True"
ToolTip='<%# "Question" + XPath("@ID") %>'
OnSelectedIndexChanged="ChoicesRadioButtonList_SelectedIndexChanged"/>
</td></tr>
</table>
<hr />
</ItemTemplate>
</asp:DataList>
</div>
</form>
</body>
</html>
Aktivieren des Teilrenderings von Seiten in einem benutzerdefinierten Steuerelement
Sie können UpdatePanel einem Benutzersteuerelement oder einem benutzerdefinierten Steuerelement hinzufügen. Möglicherweise enthält die Seite mit Ihrem Steuerelement jedoch nicht das erforderliche ScriptManager-Steuerelement, dessen EnablePartialRendering-Eigenschaft auf true festgelegt sein muss. Sie können daher in Ihrem benutzerdefinierten Steuerelement ermitteln, ob das Teilrendering von Seiten aktiviert ist, indem Sie die statische GetCurrent-Methode des ScriptManager-Steuerelements aufrufen. Wenn auf der Seite kein ScriptManager-Steuerelement vorhanden ist, gibt die GetCurrent-Methode null zurück. Andernfalls können Sie den Wert der EnablePartialRendering-Eigenschaft des ScriptManager-Steuerelements überprüfen und ein UpdatePanel-Steuerelement hinzufügen, wenn die EnablePartialRendering-Eigenschaft true zurückgibt.
Im folgenden Beispiel wird die CreateChildControls-Methode eines benutzerdefinierten Steuerelements dargestellt, das von der CompositeControl-Klasse erbt. Wenn das Teilrendering von Seiten für die Seite aktiviert ist, wird der Inhalt des benutzerdefinierten Steuerelements in einem UpdatePanel-Steuerelement abgelegt.
Protected Overrides Sub CreateChildControls()
MyBase.CreateChildControls()
Dim parent As Control
Dim container As Control
' Get a reference to the ScriptManager object for the page
' if one exists.
Dim sm As ScriptManager = ScriptManager.GetCurrent(Page)
If sm Is Nothing OrElse Not sm.EnablePartialRendering Then
' If partial rendering is not enabled, set the parent
' and container as a basic control.
container = New Control()
parent = container
Else
' If partial rendering is enabled, set the parent as
' a new UpdatePanel object and the container to the
' content template of the UpdatePanel object.
Dim up As UpdatePanel = New UpdatePanel()
container = up.ContentTemplateContainer
parent = up
End If
AddDataboundControls(container)
Controls.Add(parent)
End Sub
protected override void CreateChildControls() {
base.CreateChildControls();
Control parent;
Control container;
// Get a reference to the ScriptManager object for the page
// if one exists.
ScriptManager sm = ScriptManager.GetCurrent(Page);
if (sm == null || !sm.EnablePartialRendering)
{
// If partial rendering is not enabled, set the parent
// and container as a basic control.
container = new Control();
parent = container;
}
else
{
// If partial rendering is enabled, set the parent as
// a new UpdatePanel object and the container to the
// content template of the UpdatePanel object.
UpdatePanel up = new UpdatePanel();
container = up.ContentTemplateContainer;
parent = up;
}
AddDataboundControls(container);
Controls.Add(parent);
}
Im folgenden Beispiel wird ein benutzerdefiniertes Steuerelement dargestellt, das ein UpdatePanel-Steuerelement enthält, wenn das Teilrendering von Seiten aktiviert ist.
<%@ Page Language="VB" AutoEventWireup="true" %>
<%@ Register Namespace="UpdatePanelTutorialCustom.VB" TagPrefix="sample" %>
<!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 id="Head1" >
<title>Browse Products</title>
<script >
Protected Sub ProductsView1_RowCommand(ByVal sender As Object, ByVal e As EventArgs)
ShoppingCartList.DataSource = ProductsView1.Cart
ShoppingCartList.DataBind()
End Sub
</script>
</head>
<body>
<form id="form1" >
<div>
<asp:ScriptManager ID="ScriptManager1" EnablePartialRendering="false" />
<h2>Browse Products</h2>
<sample:ProductsView ID="ProductsView1" PageSize="5" OnRowCommand="ProductsView1_RowCommand" />
<asp:UpdatePanel ID="CartUpdatePanel">
<ContentTemplate>
<h3>Selected Items</h3>
<asp:BulletedList BulletStyle="numbered" ID="ShoppingCartList" />
</ContentTemplate>
</asp:UpdatePanel>
</div>
</form>
</body>
</html>
<%@ Page Language="C#" AutoEventWireup="true" %>
<%@ Register Namespace="UpdatePanelTutorialCustom.CS" TagPrefix="sample" %>
<!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 >
<title>Browse Products</title>
<script >
protected void ProductsView1_RowCommand(object sender, EventArgs e)
{
ShoppingCartList.DataSource = ProductsView1.Cart;
ShoppingCartList.DataBind();
}
</script>
</head>
<body>
<form id="form1" >
<div>
<asp:ScriptManager ID="ScriptManager1" EnablePartialRendering="false" />
<h2>Browse Products</h2>
<sample:ProductsView ID="ProductsView1" PageSize="5" OnRowCommand="ProductsView1_RowCommand" />
<asp:UpdatePanel ID="CartUpdatePanel">
<ContentTemplate>
<h3>Selected Items</h3>
<asp:BulletedList BulletStyle="numbered" ID="ShoppingCartList" />
</ContentTemplate>
</asp:UpdatePanel>
</div>
</form>
</body>
</html>
Imports System
Imports System.Data
Imports System.Configuration
Imports System.Collections
Imports System.Web
Imports System.Web.Security
Imports System.Web.UI.WebControls
Imports System.Web.UI.WebControls.WebParts
Imports System.Web.UI.HtmlControls
Imports System.Web.UI
Imports System.Drawing
Namespace UpdatePanelTutorialCustom.VB
Public Class ProductsView
Inherits CompositeControl
Private _pageSize As Integer
Private _cart As ArrayList
Private Shared ReadOnly EventRowCommand As Object = New Object()
Public Property PageSize() As Integer
Get
Return _pageSize
End Get
Set(ByVal value As Integer)
_pageSize = value
End Set
End Property
Public ReadOnly Property Cart() As ArrayList
Get
Return _cart
End Get
End Property
Protected Overrides Sub CreateChildControls()
MyBase.CreateChildControls()
Dim parent As Control
Dim container As Control
' Get a reference to the ScriptManager object for the page
' if one exists.
Dim sm As ScriptManager = ScriptManager.GetCurrent(Page)
If sm Is Nothing OrElse Not sm.EnablePartialRendering Then
' If partial rendering is not enabled, set the parent
' and container as a basic control.
container = New Control()
parent = container
Else
' If partial rendering is enabled, set the parent as
' a new UpdatePanel object and the container to the
' content template of the UpdatePanel object.
Dim up As UpdatePanel = New UpdatePanel()
container = up.ContentTemplateContainer
parent = up
End If
AddDataboundControls(container)
Controls.Add(parent)
End Sub
Private Sub GridView_RowCommand(ByVal sender As Object, ByVal e As GridViewCommandEventArgs)
Dim productID As String
If e.CommandName = "AddToCart" Then
productID = CType(sender, GridView).DataKeys(Convert.ToInt32(e.CommandArgument)).Value.ToString()
If _cart Is Nothing Then GetCart()
If _cart.IndexOf(productID) = -1 Then _
_cart.Add(productID)
ViewState("Cart") = _cart
End If
If e.CommandName = "RemoveFromCart" Then
productID = CType(sender, GridView).DataKeys(Convert.ToInt32(e.CommandArgument)).Value.ToString()
If _cart Is Nothing Then GetCart()
_cart.Remove(productID)
ViewState("Cart") = _cart
End If
Me.OnRowCommand(New EventArgs())
End Sub
Private Sub GetCart()
If ViewState("Cart") Is Nothing Then
_cart = New ArrayList()
Else
_cart = CType(ViewState("Cart"), ArrayList)
End If
End Sub
Custom Event RowCommand As EventHandler
RaiseEvent(ByVal sender As Object, ByVal e As EventArgs)
End RaiseEvent
AddHandler(ByVal value As EventHandler)
Events.AddHandler(EventRowCommand, value)
End AddHandler
RemoveHandler(ByVal value As EventHandler)
Events.RemoveHandler(EventRowCommand, value)
End RemoveHandler
End Event
Protected Overridable Sub OnRowCommand(ByVal e As EventArgs)
Dim handler As EventHandler = CType(Events(EventRowCommand), EventHandler)
If handler IsNot Nothing Then
handler(Me, e)
End If
End Sub
Private Sub AddDataboundControls(ByVal parent As Control)
Dim ds As SqlDataSource = New SqlDataSource()
ds.ID = "ProductsSqlDataSource"
ds.ConnectionString = _
ConfigurationManager.ConnectionStrings("AdventureWorksConnectionString").ConnectionString
ds.SelectCommand = _
"SELECT Production.ProductDescription.Description, Production.Product.Name, Production.ProductPhoto.ThumbnailPhotoFileName, " & _
"Production.Product.ProductID " & _
"FROM Production.Product INNER JOIN " & _
"Production.ProductProductPhoto ON Production.Product.ProductID = Production.ProductProductPhoto.ProductID INNER JOIN " & _
"Production.ProductPhoto ON Production.ProductProductPhoto.ProductPhotoID = Production.ProductPhoto.ProductPhotoID INNER JOIN " & _
"Production.ProductModelProductDescriptionCulture ON " & _
"Production.Product.ProductModelID = Production.ProductModelProductDescriptionCulture.ProductModelID INNER JOIN " & _
"Production.ProductDescription ON " & _
"Production.ProductModelProductDescriptionCulture.ProductDescriptionID = Production.ProductDescription.ProductDescriptionID"
Dim gv As GridView = New GridView()
gv.ID = "ProductsGridView"
gv.DataSourceID = ds.ID
gv.AutoGenerateColumns = False
gv.DataKeyNames = New String() {"ProductID"}
gv.GridLines = GridLines.None
gv.HeaderStyle.BackColor = Color.LightGray
gv.AlternatingRowStyle.BackColor = Color.LightBlue
gv.AllowPaging = True
gv.PageSize = _pageSize
AddHandler gv.RowCommand, AddressOf Me.GridView_RowCommand
Dim if1 As ImageField = New ImageField()
if1.HeaderText = "Product"
if1.DataImageUrlField = "ThumbnailPhotoFileName"
if1.DataImageUrlFormatString = "..\images\thumbnails\{0}"
Dim bf1 As BoundField = New BoundField()
bf1.HeaderText = "Name"
bf1.DataField = "Name"
Dim bf2 As BoundField = New BoundField()
bf2.HeaderText = "Description"
bf2.DataField = "Description"
Dim btf1 As ButtonField = New ButtonField()
btf1.Text = "Add"
btf1.CommandName = "AddToCart"
Dim btf2 As ButtonField = New ButtonField()
btf2.Text = "Remove"
btf2.CommandName = "RemoveFromCart"
gv.Columns.Add(if1)
gv.Columns.Add(bf1)
gv.Columns.Add(bf2)
gv.Columns.Add(btf1)
gv.Columns.Add(btf2)
parent.Controls.Add(New LiteralControl("<br />"))
parent.Controls.Add(gv)
parent.Controls.Add(New LiteralControl("<br />"))
parent.Controls.Add(ds)
End Sub
End Class
End Namespace
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Web.UI;
using System.Drawing;
namespace UpdatePanelTutorialCustom.CS
{
public class ProductsView : CompositeControl
{
private int _pageSize;
private ArrayList _cart;
private static readonly object EventRowCommand = new object();
public int PageSize
{
get { return _pageSize; }
set { _pageSize = value; }
}
public ArrayList Cart
{
get { return _cart; }
}
protected override void CreateChildControls() {
base.CreateChildControls();
Control parent;
Control container;
// Get a reference to the ScriptManager object for the page
// if one exists.
ScriptManager sm = ScriptManager.GetCurrent(Page);
if (sm == null || !sm.EnablePartialRendering)
{
// If partial rendering is not enabled, set the parent
// and container as a basic control.
container = new Control();
parent = container;
}
else
{
// If partial rendering is enabled, set the parent as
// a new UpdatePanel object and the container to the
// content template of the UpdatePanel object.
UpdatePanel up = new UpdatePanel();
container = up.ContentTemplateContainer;
parent = up;
}
AddDataboundControls(container);
Controls.Add(parent);
}
private void GridView_RowCommand(object sender, GridViewCommandEventArgs e)
{
string productID;
if (e.CommandName == "AddToCart")
{
productID = ((GridView)sender).DataKeys[Convert.ToInt32(e.CommandArgument)].Value.ToString();
if (_cart == null) { GetCart(); }
if (_cart.IndexOf(productID) == -1)
_cart.Add(productID);
ViewState["Cart"] = _cart;
}
if (e.CommandName == "RemoveFromCart")
{
productID = ((GridView)sender).DataKeys[Convert.ToInt32(e.CommandArgument)].Value.ToString();
if (_cart == null) { GetCart(); }
_cart.Remove(productID);
ViewState["Cart"] = _cart;
}
this.OnRowCommand(new EventArgs());
}
private void GetCart()
{
if (ViewState["Cart"] == null)
_cart = new ArrayList();
else
_cart = (ArrayList)ViewState["Cart"];
}
public event EventHandler RowCommand
{
add { Events.AddHandler(EventRowCommand, value); }
remove { Events.RemoveHandler(EventRowCommand, value); }
}
protected virtual void OnRowCommand(EventArgs e)
{
EventHandler handler = (EventHandler)Events[EventRowCommand];
if (handler != null)
{
handler(this, e);
}
}
private void AddDataboundControls(Control parent)
{
SqlDataSource ds = new SqlDataSource();
ds.ID = "ProductsSqlDataSource";
ds.ConnectionString =
ConfigurationManager.ConnectionStrings["AdventureWorksConnectionString"].ConnectionString;
ds.SelectCommand =
"SELECT Production.ProductDescription.Description, Production.Product.Name, Production.ProductPhoto.ThumbnailPhotoFileName, " +
"Production.Product.ProductID " +
"FROM Production.Product INNER JOIN " +
"Production.ProductProductPhoto ON Production.Product.ProductID = Production.ProductProductPhoto.ProductID INNER JOIN " +
"Production.ProductPhoto ON Production.ProductProductPhoto.ProductPhotoID = Production.ProductPhoto.ProductPhotoID INNER JOIN " +
"Production.ProductModelProductDescriptionCulture ON " +
"Production.Product.ProductModelID = Production.ProductModelProductDescriptionCulture.ProductModelID INNER JOIN " +
"Production.ProductDescription ON " +
"Production.ProductModelProductDescriptionCulture.ProductDescriptionID = Production.ProductDescription.ProductDescriptionID";
GridView gv = new GridView();
gv.ID = "ProductsGridView";
gv.DataSourceID = ds.ID;
gv.AutoGenerateColumns = false;
gv.DataKeyNames = new string[] { "ProductID" };
gv.GridLines = GridLines.None;
gv.HeaderStyle.BackColor = Color.LightGray;
gv.AlternatingRowStyle.BackColor = Color.LightBlue;
gv.AllowPaging = true;
gv.PageSize = _pageSize;
gv.RowCommand += this.GridView_RowCommand;
ImageField if1 = new ImageField();
if1.HeaderText = "Product";
if1.DataImageUrlField = "ThumbnailPhotoFileName";
if1.DataImageUrlFormatString = @"..\images\thumbnails\{0}";
BoundField bf1 = new BoundField();
bf1.HeaderText = "Name";
bf1.DataField = "Name";
BoundField bf2 = new BoundField();
bf2.HeaderText = "Description";
bf2.DataField = "Description";
ButtonField btf1 = new ButtonField();
btf1.Text = "Add";
btf1.CommandName = "AddToCart";
ButtonField btf2 = new ButtonField();
btf2.Text = "Remove";
btf2.CommandName = "RemoveFromCart";
gv.Columns.Add(if1);
gv.Columns.Add(bf1);
gv.Columns.Add(bf2);
gv.Columns.Add(btf1);
gv.Columns.Add(btf2);
parent.Controls.Add(new LiteralControl("<br />"));
parent.Controls.Add(gv);
parent.Controls.Add(new LiteralControl("<br />"));
parent.Controls.Add(ds);
}
}
}
Siehe auch
Konzepte
Übersicht über das Teilrendering von Seiten