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ListView.ItemDeleted Событие

  • Ссылка

Определение

Пространство имен:
System.Web.UI.WebControls
Сборка:
System.Web.Extensions.dll

Происходит при запросе операции удаления, после того как элемент управления ListView удаляет элемент.

public:
 event EventHandler<System::Web::UI::WebControls::ListViewDeletedEventArgs ^> ^ ItemDeleted;
public event EventHandler<System.Web.UI.WebControls.ListViewDeletedEventArgs> ItemDeleted;
member this.ItemDeleted : EventHandler<System.Web.UI.WebControls.ListViewDeletedEventArgs> 
Public Custom Event ItemDeleted As EventHandler(Of ListViewDeletedEventArgs)

Тип события

EventHandler<ListViewDeletedEventArgs>

Примеры

В следующем примере показано, как добавить обработчик событий для ItemDeleted события.

<%@ 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 Page_Load()
    {
        Message.Text = String.Empty;
    }
    
    void ContactsListView_ItemDeleted(Object sender, ListViewDeletedEventArgs e)
    {
        // Determine whether an exception occurred during the delete operation.
        if (e.Exception == null)
        {
            // Ensure that a record was deleted.
            if (e.AffectedRows > 0)
            {
                Message.Text = e.AffectedRows + " item(s) deleted successfully.";
            }
            else
            {
                Message.Text = "No item was deleted.";
            }
        }
        else
        {
            // Insert the code to handle the exception here.

            // Indicate that the exception has been handled.
            e.ExceptionHandled = true;
            Message.Text = "An error occurred during the delete operation.";
        }
    }
    
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>ListViewDeletedEventArgs Example</title>
  </head>
  <body>
    <form id="form1" runat="server">
        
      <h3>ListViewDeletedEventArgs Example</h3>
            
      <asp:Label ID="Message"
        ForeColor="Red"          
        runat="server"/>
      <br/>
            
      <asp:ListView ID="ContactsListView" 
        DataSourceID="ContactsDataSource" 
        DataKeyNames="ContactID"
        OnItemDeleted="ContactsListView_ItemDeleted"  
        runat="server">
        <LayoutTemplate>
          <table cellpadding="2" runat="server" id="tblContacts" width="640px">
            <tr runat="server" id="itemPlaceholder" />
          </table>
          <asp:DataPager runat="server" ID="PeopleDataPager" PageSize="12">
            <Fields>
              <asp:NextPreviousPagerField 
                ShowFirstPageButton="true" ShowLastPageButton="true"
                FirstPageText="|&lt;&lt; " LastPageText=" &gt;&gt;|"
                NextPageText=" &gt; " PreviousPageText=" &lt; " />
            </Fields>
          </asp:DataPager>
        </LayoutTemplate>
        <ItemTemplate>
          <tr runat="server">
            <td valign="top">
              <asp:Label ID="FirstNameLabel" runat="server" Text='<%#Eval("FirstName") %>' />
              <asp:Label ID="LastNameLabel" runat="server" Text='<%#Eval("LastName") %>' />
            </td>
            <td>
              <asp:Label ID="EmailLabel" runat="server" Text='<%#Eval("EmailAddress") %>' />
            </td>
            <td>
              <asp:LinkButton ID="DeleteButton" runat="server" 
                CommandName="Delete" 
                Text="Delete" 
                OnClientClick="return confirm('Are you sure?');" />
            </td>
          </tr>
        </ItemTemplate>
      </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"
        DeleteCommand="DELETE FROM Person.Contact WHERE [ContactID] = @ContactID">
        <DeleteParameters>
            <asp:Parameter Name="ContactID" Type="Int32" />
        </DeleteParameters>
      </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">

    Sub Page_Load()
        Message.Text = String.Empty
    End Sub
    
    Sub ContactsListView_ItemDeleted(sender As Object, e As ListViewDeletedEventArgs)

        ' Determine whether an exception occurred during the delete operation.
        If e.Exception Is Nothing Then
            ' Ensure that a record was deleted.
            If e.AffectedRows > 0 Then
                Message.Text = e.AffectedRows.ToString() & _
                    " item(s) deleted successfully."
            Else
                Message.Text = "No item was deleted."
            End If
        Else
            ' Insert the code to handle the exception here.

            ' Indicate that the exception has been handled.
            e.ExceptionHandled = true
            Message.Text = "An error occurred during the delete operation."
        End If
    End Sub
    
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head id="Head1" runat="server">
    <title>ListViewDeletedEventArgs Example</title>
  </head>
  <body>
    <form id="form1" runat="server">
        
      <h3>ListViewDeletedEventArgs Example</h3>
            
      <asp:Label ID="Message"
        ForeColor="Red"          
        runat="server"/>
      <br/>
            
      <asp:ListView ID="ContactsListView" 
        DataSourceID="ContactsDataSource" 
        DataKeyNames="ContactID"
        OnItemDeleted="ContactsListView_ItemDeleted"  
        runat="server">
        <LayoutTemplate>
          <table cellpadding="2" runat="server" id="tblContacts" width="640px">
            <tr runat="server" id="itemPlaceholder" />
          </table>
          <asp:DataPager runat="server" ID="PeopleDataPager" PageSize="12">
            <Fields>
              <asp:NextPreviousPagerField 
                ShowFirstPageButton="true" ShowLastPageButton="true"
                FirstPageText="|&lt;&lt; " LastPageText=" &gt;&gt;|"
                NextPageText=" &gt; " PreviousPageText=" &lt; " />
            </Fields>
          </asp:DataPager>
        </LayoutTemplate>
        <ItemTemplate>
          <tr runat="server">
            <td valign="top">
              <asp:Label ID="FirstNameLabel" runat="server" Text='<%#Eval("FirstName") %>' />
              <asp:Label ID="LastNameLabel" runat="server" Text='<%#Eval("LastName") %>' />
            </td>
            <td>
              <asp:Label ID="EmailLabel" runat="server" Text='<%#Eval("EmailAddress") %>' />
            </td>
            <td>
              <asp:LinkButton ID="DeleteButton" runat="server" 
                CommandName="Delete" 
                Text="Delete" 
                OnClientClick="return confirm('Are you sure?');" />
            </td>
          </tr>
        </ItemTemplate>
      </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"
        DeleteCommand="DELETE FROM Person.Contact WHERE [ContactID] = @ContactID">
        <DeleteParameters>
            <asp:Parameter Name="ContactID" Type="Int32" />
        </DeleteParameters>
      </asp:SqlDataSource>
      
    </form>
  </body>
</html>

Комментарии

Событие ItemDeleted возникает при нажатии кнопки Удалить элемента или вызове DeleteItem метода после удаления элемента элементом ListView управления. (Кнопка "Удалить" — это элемент управления кнопкой, для свойства которого CommandName задано значение "Удалить".) Это позволяет выполнять настраиваемую подпрограмму при каждом возникновении этого события, например проверять результаты операции удаления.

Объект ListViewDeletedEventArgs передается обработчику событий, что позволяет определить количество строк, затронутых в источнике данных. Он также позволяет определить, какие исключения могли возникнуть. Можно указать, было ли обработано исключение в обработчике событий, задав свойству ExceptionHandledListViewDeletedEventArgs объекта значение true.

Дополнительные сведения об обработке событий см. в разделе Обработка и создание событий.

Применяется к

См. также раздел