ListView.Sorting Ereignis
Definition
Wichtig
Einige Informationen beziehen sich auf Vorabversionen, die vor dem Release ggf. grundlegend überarbeitet werden. Microsoft übernimmt hinsichtlich der hier bereitgestellten Informationen keine Gewährleistungen, seien sie ausdrücklich oder konkludent.
Tritt ein, wenn ein Sortiervorgang angefordert wird, jedoch bevor der Sortiervorgang vom ListView-Steuerelement behandelt wird.
public:
event EventHandler<System::Web::UI::WebControls::ListViewSortEventArgs ^> ^ Sorting;
public event EventHandler<System.Web.UI.WebControls.ListViewSortEventArgs> Sorting;
member this.Sorting : EventHandler<System.Web.UI.WebControls.ListViewSortEventArgs>
Public Custom Event Sorting As EventHandler(Of ListViewSortEventArgs)
Ereignistyp
Beispiele
Das folgende Beispiel zeigt, wie sie einen Ereignishandler für das Sorting Ereignis erstellen.
<%@ 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">
//<Snippet2>
void ContactsListView_Sorting(Object sender, ListViewSortEventArgs e)
{
// Check the sort direction to set the image URL accordingly.
string imgUrl;
if (e.SortDirection == SortDirection.Ascending)
imgUrl = "~/images/ascending.gif";
else
imgUrl = "~/images/descending.gif";
// Check which field is being sorted
// to set the visibility of the image controls.
Image sortImage1 = (Image) ContactsListView.FindControl("SortImage1");
Image sortImage2 = (Image)ContactsListView.FindControl("SortImage2");
Image sortImage3 = (Image)ContactsListView.FindControl("SortImage3");
switch (e.SortExpression)
{
case "FirstName":
sortImage1.Visible = true;
sortImage1.ImageUrl = imgUrl;
sortImage2.Visible = false;
sortImage3.Visible = false;
break;
case "LastName":
sortImage1.Visible = false;
sortImage2.Visible = true;
sortImage2.ImageUrl = imgUrl;
sortImage3.Visible = false;
break;
case "EmailAddress":
sortImage1.Visible = false;
sortImage2.Visible = false;
sortImage3.Visible = true;
sortImage3.ImageUrl = imgUrl;
break;
}
}
//</Snippet2>
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>ListView Sorting Example</title>
<style type="text/css">
body { font: 10pt Trebuchet MS, Arial, Tahoma; }
td { border: 1px solid #E6E6FA; }
.header { background: #B0C4DE; }
.alternatingItem { background: #edf5fd; }
</style>
</head>
<body>
<form id="form1" runat="server">
<h3>ListView Sorting Example</h3>
<asp:ListView ID="ContactsListView"
DataSourceID="ContactsDataSource"
OnSorting="ContactsListView_Sorting"
runat="server">
<LayoutTemplate>
<table width="640px" runat="server" id="tblContacts">
<tr class="header" align="center" runat="server">
<td>
<asp:LinkButton runat="server" ID="SortByFirstNameButton"
CommandName="Sort" Text="First Name"
CommandArgument="FirstName"/>
<asp:Image runat="server" ID="SortImage1"
ImageUrl="~/images/ascending.gif" Visible="false" />
</td>
<td>
<asp:LinkButton runat="server" ID="SortByLastNameButton"
CommandName="Sort" Text="Last Name"
CommandArgument="LastName" />
<asp:Image runat="server" ID="SortImage2"
ImageUrl="~/images/ascending.gif" Visible="false" />
</td>
<td>
<asp:LinkButton runat="server" ID="SortByEmailButton"
CommandName="Sort" Text="Email Address"
CommandArgument="EmailAddress" />
<asp:Image runat="server" ID="SortImage3"
ImageUrl="~/images/ascending.gif" Visible="false" />
</td>
</tr>
<tr runat="server" id="itemPlaceholder" />
</table>
<asp:DataPager runat="server" ID="PeopleDataPager" PageSize="12">
<Fields>
<asp:NextPreviousPagerField
ShowFirstPageButton="true" ShowLastPageButton="true"
FirstPageText="|<< " LastPageText=" >>|"
NextPageText=" > " PreviousPageText=" < " />
</Fields>
</asp:DataPager>
</LayoutTemplate>
<ItemTemplate>
<tr runat="server">
<td>
<asp:Label ID="FirstNameLabel" runat="server" Text='<%#Eval("FirstName") %>' />
</td>
<td>
<asp:Label ID="LastNameLabel" runat="server" Text='<%#Eval("LastName") %>' />
</td>
<td>
<asp:Label ID="EmailLabel" runat="server" Text='<%#Eval("EmailAddress") %>' />
</td>
</tr>
</ItemTemplate>
<AlternatingItemTemplate>
<tr class="alternatingItem" runat="server">
<td>
<asp:Label ID="FirstNameLabel" runat="server" Text='<%#Eval("FirstName") %>' />
</td>
<td>
<asp:Label ID="LastNameLabel" runat="server" Text='<%#Eval("LastName") %>' />
</td>
<td>
<asp:Label ID="EmailLabel" runat="server" Text='<%#Eval("EmailAddress") %>' />
</td>
</tr>
</AlternatingItemTemplate>
</asp:ListView>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the AdventureWorks sample database. Use an ASP.NET -->
<!-- expression to retrieve the connection string value -->
<!-- from the Web.config file. -->
<asp:SqlDataSource ID="ContactsDataSource" runat="server"
ConnectionString="<%$ ConnectionStrings:AdventureWorks_DataConnectionString %>"
SelectCommand="SELECT [ContactID], [FirstName], [LastName], [EmailAddress]
FROM Person.Contact" >
</asp:SqlDataSource>
</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">
'<Snippet2>
Sub ContactsListView_Sorting(ByVal sender As Object, ByVal e As ListViewSortEventArgs)
' Check the sort direction to set the image URL accordingly.
Dim imgUrl As String
If e.SortDirection = SortDirection.Ascending Then
imgUrl = "~/images/ascending.gif"
Else
imgUrl = "~/images/descending.gif"
End If
' Check which field is being sorted
' to set the visibility of the image controls.
Dim sortImage1 As Image = CType(ContactsListView.FindControl("SortImage1"), Image)
Dim sortImage2 As Image = CType(ContactsListView.FindControl("SortImage2"), Image)
Dim sortImage3 As Image = CType(ContactsListView.FindControl("SortImage3"), Image)
Select Case e.SortExpression
Case "FirstName"
sortImage1.Visible = True
sortImage1.ImageUrl = imgUrl
sortImage2.Visible = False
sortImage3.Visible = False
Case "LastName"
sortImage1.Visible = False
sortImage2.Visible = True
sortImage2.ImageUrl = imgUrl
sortImage3.Visible = False
Case "EmailAddress"
sortImage1.Visible = False
sortImage2.Visible = False
sortImage3.Visible = True
sortImage3.ImageUrl = imgUrl
End Select
End Sub
'</Snippet2>
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>ListView Sorting Example</title>
<style type="text/css">
body { font: 10pt Trebuchet MS, Arial, Tahoma; }
td { border: 1px solid #E6E6FA; }
.header { background: #B0C4DE; }
.alternatingItem { background: #edf5fd; }
</style>
</head>
<body>
<form id="form1" runat="server">
<h3>ListView Sorting Example</h3>
<asp:ListView ID="ContactsListView"
DataSourceID="ContactsDataSource"
OnSorting="ContactsListView_Sorting"
runat="server">
<LayoutTemplate>
<table width="640px" runat="server" id="tblContacts">
<tr class="header" align="center" runat="server">
<td>
<asp:LinkButton runat="server" ID="SortByFirstNameButton"
CommandName="Sort" Text="First Name"
CommandArgument="FirstName"/>
<asp:Image runat="server" ID="SortImage1"
ImageUrl="~/images/ascending.gif" Visible="false" />
</td>
<td>
<asp:LinkButton runat="server" ID="SortByLastNameButton"
CommandName="Sort" Text="Last Name"
CommandArgument="LastName" />
<asp:Image runat="server" ID="SortImage2"
ImageUrl="~/images/ascending.gif" Visible="false" />
</td>
<td>
<asp:LinkButton runat="server" ID="SortByEmailButton"
CommandName="Sort" Text="Email Address"
CommandArgument="EmailAddress" />
<asp:Image runat="server" ID="SortImage3"
ImageUrl="~/images/ascending.gif" Visible="false" />
</td>
</tr>
<tr runat="server" id="itemPlaceholder" />
</table>
<asp:DataPager runat="server" ID="PeopleDataPager" PageSize="12">
<Fields>
<asp:NextPreviousPagerField
ShowFirstPageButton="true" ShowLastPageButton="true"
FirstPageText="|<< " LastPageText=" >>|"
NextPageText=" > " PreviousPageText=" < " />
</Fields>
</asp:DataPager>
</LayoutTemplate>
<ItemTemplate>
<tr runat="server">
<td>
<asp:Label ID="FirstNameLabel" runat="server" Text='<%#Eval("FirstName") %>' />
</td>
<td>
<asp:Label ID="LastNameLabel" runat="server" Text='<%#Eval("LastName") %>' />
</td>
<td>
<asp:Label ID="EmailLabel" runat="server" Text='<%#Eval("EmailAddress") %>' />
</td>
</tr>
</ItemTemplate>
<AlternatingItemTemplate>
<tr class="alternatingItem" runat="server">
<td>
<asp:Label ID="FirstNameLabel" runat="server" Text='<%#Eval("FirstName") %>' />
</td>
<td>
<asp:Label ID="LastNameLabel" runat="server" Text='<%#Eval("LastName") %>' />
</td>
<td>
<asp:Label ID="EmailLabel" runat="server" Text='<%#Eval("EmailAddress") %>' />
</td>
</tr>
</AlternatingItemTemplate>
</asp:ListView>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the AdventureWorks sample database. Use an ASP.NET -->
<!-- expression to retrieve the connection string value -->
<!-- from the Web.config file. -->
<asp:SqlDataSource ID="ContactsDataSource" runat="server"
ConnectionString="<%$ ConnectionStrings:AdventureWorks_DataConnectionString %>"
SelectCommand="SELECT [ContactID], [FirstName], [LastName], [EmailAddress]
FROM Person.Contact" >
</asp:SqlDataSource>
</form>
</body>
</html>
Hinweise
Das Sorting Ereignis wird ausgelöst, wenn auf eine Sortierungsschaltfläche geklickt oder die Sort -Methode aufgerufen wird, aber bevor das ListView Steuerelement den Sortiervorgang verarbeitet. (Eine Sortierschaltfläche ist ein Schaltflächensteuerelement, dessen CommandName Eigenschaft auf "Sort" festgelegt ist.) Dadurch können Sie immer dann eine benutzerdefinierte Routine ausführen, wenn dieses Ereignis auftritt, z. B. das Anpassen des Sortierausdrucks.
Ein ListViewSortEventArgs -Objekt wird an den Ereignishandler übergeben, sodass Sie den Sortierausdruck für die Spalte bestimmen können. Außerdem können Sie angeben, dass der Sortiervorgang abgebrochen werden soll. Um den Sortiervorgang abzubrechen, legen Sie die Cancel -Eigenschaft des ListViewSortEventArgs -Objekts auf fest true
.
Weitere Informationen zum Behandeln von Ereignissen finden Sie unter behandeln und Auslösen von Ereignissen.