ListView.PagePropertiesChanging Událost
Definice
Důležité
Některé informace platí pro předběžně vydaný produkt, který se může zásadně změnit, než ho výrobce nebo autor vydá. Microsoft neposkytuje žádné záruky, výslovné ani předpokládané, týkající se zde uváděných informací.
Nastane, když se změní vlastnosti stránky, ale před tím, než ListView ovládací prvek nastaví nové hodnoty.
public:
event EventHandler<System::Web::UI::WebControls::PagePropertiesChangingEventArgs ^> ^ PagePropertiesChanging;public event EventHandler<System.Web.UI.WebControls.PagePropertiesChangingEventArgs> PagePropertiesChanging;member this.PagePropertiesChanging : EventHandler<System.Web.UI.WebControls.PagePropertiesChangingEventArgs> Public Custom Event PagePropertiesChanging As EventHandler(Of PagePropertiesChangingEventArgs) Event Type
Příklady
Následující příklad ukazuje, jak vytvořit obslužnou rutinu PagePropertiesChanging události pro událost.
<%@ 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>
protected void DeleteButton_Click(object sender, EventArgs e)
{
//Check if an item is selected to delete it.
if (ContactsListView.SelectedIndex >= 0)
ContactsListView.DeleteItem(ContactsListView.SelectedIndex);
else
Message.Text = "No contact was selected.";
}
// </Snippet2>
protected void ContactsListView_ItemDeleted(object sender, ListViewDeletedEventArgs e)
{
//Check if an exception occurred to display an error message.
if (e.Exception != null)
{
Message.Text = "An exception occurred deleting the contact.";
e.ExceptionHandled = true;
}
else
{
// Clear the selected index.
ContactsListView.SelectedIndex = -1;
}
}
protected void ContactsListView_PagePropertiesChanging(object sender,
PagePropertiesChangingEventArgs e)
{
//Clear the selected index.
ContactsListView.SelectedIndex = -1;
}
protected void Page_Load(object sender, EventArgs e)
{
//Clear the message label.
Message.Text = "";
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>ListView DeleteItem Example</title>
<style type="text/css">
body
{
font-size: 10pt;
font-family: Trebuchet MS, Arial, Tahoma;
text-align:center;
}
.item { background-color: #E0FFFF }
.selectedItem { background-color: #B0E0E6 }
</style>
</head>
<body>
<form id="form1" runat="server">
<h3>ListView DeleteItem Example</h3>
<asp:ListView ID="ContactsListView"
DataSourceID="ContactsDataSource"
DataKeyNames="ContactID"
OnItemDeleted="ContactsListView_ItemDeleted"
OnPagePropertiesChanging="ContactsListView_PagePropertiesChanging"
runat="server" >
<LayoutTemplate>
<table cellpadding="2" width="640px" id="tblProducts" runat="server">
<tr runat="server">
<th runat="server"> </th>
<th runat="server">ID</th>
<th runat="server">Account Number</th>
<th runat="server">LastName</th>
<th runat="server">Preferred Vendor</th>
</tr>
<tr runat="server" id="itemPlaceholder" />
</table>
<asp:DataPager ID="ContactsDataPager" runat="server" PageSize="15">
<Fields>
<asp:NextPreviousPagerField ButtonType="Button"
ShowFirstPageButton="true"
ShowNextPageButton="false"
ShowPreviousPageButton="false" />
<asp:NumericPagerField ButtonCount="10" />
<asp:NextPreviousPagerField ButtonType="Button"
ShowLastPageButton="true"
ShowNextPageButton="false"
ShowPreviousPageButton="false" />
</Fields>
</asp:DataPager>
</LayoutTemplate>
<ItemTemplate>
<tr class="item" runat="server">
<td>
<asp:LinkButton ID="SelectButton" runat="server" CommandName="Select" Text="Select" />
</td>
<td>
<asp:Label ID="ContactIDLabel" runat="server" Text='<%# Eval("ContactID") %>' />
</td>
<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>
<SelectedItemTemplate>
<tr class="selectedItem" runat="server">
<td> </td>
<td>
<asp:Label ID="ContactIDLabel" runat="server" Text='<%# Eval("ContactID") %>' />
</td>
<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>
</SelectedItemTemplate>
</asp:ListView>
<br />
<br />
<asp:Button ID="DeleteButton"
Text="Delete Selected Contact"
OnClick="DeleteButton_Click"
runat="server" />
<br />
<asp:Label ID="Message"
ForeColor="Red"
runat="server"/>
<br/>
<!-- 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"
DeleteCommand="DELETE FROM Person.Contact WHERE (ContactID = @ContactID)" >
</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>
Protected Sub DeleteButton_Click(ByVal sender As Object, ByVal e As EventArgs)
' Check if an item is selected to delete it.
If ContactsListView.SelectedIndex >= 0 Then
ContactsListView.DeleteItem(ContactsListView.SelectedIndex)
Else
Message.Text = "No contact was selected."
End If
End Sub
' </Snippet2>
Protected Sub ContactsListView_ItemDeleted(ByVal sender As Object, _
ByVal e As ListViewDeletedEventArgs)
' Check if an exception occurred to display an error message.
If Not (e.Exception Is Nothing) Then
Message.Text = "An exception occurred deleting the contact."
e.ExceptionHandled = True
Else
' Clear the selected index.
ContactsListView.SelectedIndex = -1
End If
End Sub
Protected Sub ContactsListView_PagePropertiesChanging(ByVal sender As Object, _
ByVal e As PagePropertiesChangingEventArgs)
' Clear the selected index.
ContactsListView.SelectedIndex = -1
End Sub
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
' Clear the message label.
Message.Text = ""
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>ListView DeleteItem Example</title>
<style type="text/css">
body
{
font-size: 10pt;
font-family: Trebuchet MS, Arial, Tahoma;
text-align:center;
}
.item { background-color: #E0FFFF }
.selectedItem { background-color: #B0E0E6 }
</style>
</head>
<body>
<form id="form1" runat="server">
<h3>ListView DeleteItem Example</h3>
<asp:ListView ID="ContactsListView"
DataSourceID="ContactsDataSource"
DataKeyNames="ContactID"
OnItemDeleted="ContactsListView_ItemDeleted"
OnPagePropertiesChanging="ContactsListView_PagePropertiesChanging"
runat="server" >
<LayoutTemplate>
<table cellpadding="2" width="640px" id="tblProducts" runat="server">
<tr runat="server">
<th runat="server"> </th>
<th runat="server">ID</th>
<th runat="server">Account Number</th>
<th runat="server">LastName</th>
<th runat="server">Preferred Vendor</th>
</tr>
<tr runat="server" id="itemPlaceholder" />
</table>
<asp:DataPager ID="ContactsDataPager" runat="server" PageSize="15">
<Fields>
<asp:NextPreviousPagerField ButtonType="Button"
ShowFirstPageButton="true"
ShowNextPageButton="false"
ShowPreviousPageButton="false" />
<asp:NumericPagerField ButtonCount="10" />
<asp:NextPreviousPagerField ButtonType="Button"
ShowLastPageButton="true"
ShowNextPageButton="false"
ShowPreviousPageButton="false" />
</Fields>
</asp:DataPager>
</LayoutTemplate>
<ItemTemplate>
<tr class="item" runat="server">
<td>
<asp:LinkButton ID="SelectButton" runat="server" CommandName="Select" Text="Select" />
</td>
<td>
<asp:Label ID="ContactIDLabel" runat="server" Text='<%# Eval("ContactID") %>' />
</td>
<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>
<SelectedItemTemplate>
<tr class="selectedItem" runat="server">
<td> </td>
<td>
<asp:Label ID="ContactIDLabel" runat="server" Text='<%# Eval("ContactID") %>' />
</td>
<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>
</SelectedItemTemplate>
</asp:ListView>
<br />
<br />
<asp:Button ID="DeleteButton"
Text="Delete Selected Contact"
OnClick="DeleteButton_Click"
runat="server" />
<br />
<asp:Label ID="Message"
ForeColor="Red"
runat="server"/>
<br/>
<!-- 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"
DeleteCommand="DELETE FROM Person.Contact WHERE (ContactID = @ContactID)" >
</asp:SqlDataSource>
</form>
</body>
</html>
Poznámky
Událost PagePropertiesChanging je vyvolána při změně vlastností stránky, ale předtím, než ListView ovládací prvek nastaví nové hodnoty pomocí SetPageProperties metody. To vám umožní provádět vlastní rutinu pokaždé, když dojde k této události, například vymazání SelectedIndex vlastností nebo EditIndex .
PagePropertiesChangingEventArgs Objekt je předán obslužné rutině události, což vám umožní určit index prvního záznamu zobrazeného na stránce. Umožňuje také určit maximální počet položek, které se mají zobrazit na jedné stránce.
Další informace o zpracování událostí najdete v tématu Zpracování a vyvolávání událostí.
Platí pro
Viz také
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