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SqlDataSourceView.OnUpdated(SqlDataSourceStatusEventArgs) Metodo

Definizione

Genera l'evento Updated dopo che il controllo SqlDataSource ha completato un'operazione di aggiornamento.

protected:
 virtual void OnUpdated(System::Web::UI::WebControls::SqlDataSourceStatusEventArgs ^ e);
protected virtual void OnUpdated (System.Web.UI.WebControls.SqlDataSourceStatusEventArgs e);
abstract member OnUpdated : System.Web.UI.WebControls.SqlDataSourceStatusEventArgs -> unit
override this.OnUpdated : System.Web.UI.WebControls.SqlDataSourceStatusEventArgs -> unit
Protected Overridable Sub OnUpdated (e As SqlDataSourceStatusEventArgs)

Parametri

e
SqlDataSourceStatusEventArgs

Oggetto SqlDataSourceStatusEventArgs che contiene i dati dell'evento.

Esempio

Nell'esempio di codice seguente viene illustrato come visualizzare e aggiornare i dati recuperati da un database ODBC in un GridView controllo. Dopo l'aggiornamento di un record, l'evento Updated viene gestito da un gestore eventi per eseguire un passaggio di post-elaborazione in cui viene inviata una notifica di messaggio di posta elettronica.

<%@Page  Language="C#" %>
<%@Import Namespace="System.Web.Mail" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

 private void OnDSUpdatedHandler(Object source, SqlDataSourceStatusEventArgs e) {
    if (e.AffectedRows > 0) {
        // Perform any additional processing, such as sending an email notification.
        Label1.Text = Request.LogonUserIdentity.Name +
            " changed user information successfully!";
    }
    else {
        Label1.Text = "No data updated!";
    }
 }
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>ASP.NET Example</title>
</head>
<body>
    <!-- This example uses a Northwind database that is hosted by an ODBC-compliant
         database. To run this sample, create an ODBC DSN to any database that hosts
         the Northwind database, including Microsoft SQL Server or Microsoft Access,
         change the name of the DSN in the ConnectionString, and view the page.
    -->
    <form id="form1" runat="server">

      <asp:SqlDataSource
          id="SqlDataSource1"
          runat="server"
          ProviderName="System.Data.Odbc"
          DataSourceMode="DataSet"
          ConnectionString="dsn=myodbc3dsn;"
          SelectCommand="SELECT EmployeeID,FirstName,LastName,Title FROM Employees"
          UpdateCommand="Update Employees SET FirstName=?,LastName=?,Title=? WHERE EmployeeID=?"
          OnUpdated="OnDSUpdatedHandler">
      </asp:SqlDataSource>

      <asp:GridView
          id="GridView1"
          runat="server"
          AutoGenerateColumns="False"
          DataKeyNames="EmployeeID"
          AutoGenerateEditButton="True"
          DataSourceID="SqlDataSource1">
          <columns>
              <asp:BoundField HeaderText="First Name" DataField="FirstName" />
              <asp:BoundField HeaderText="Last Name" DataField="LastName" />
              <asp:BoundField HeaderText="Title" DataField="Title" />
          </columns>
      </asp:GridView>

      <asp:Label
          id="Label1"
          runat="server">
      </asp:Label>

    </form>
  </body>
</html>
<%@Page  Language="VB" %>
<%@Import Namespace="System.Web.Mail" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

 Sub OnDSUpdatedHandler(ByVal source As Object, ByVal e As SqlDataSourceStatusEventArgs)
    If e.AffectedRows > 0 Then
        ' Perform any additional processing, such as setting a status label.
        Label1.Text = Request.LogonUserIdentity.Name & _
            " changed user information successfully!"
    Else
        Label1.Text = "No data updated!"
    End If
 End Sub 'OnDSUpdatedHandler

</script>


<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>ASP.NET Example</title>
</head>
<body>
    <!-- This example uses a Northwind database that is hosted by an ODBC-compliant
         database. To run this sample, create an ODBC DSN to any database that hosts
         the Northwind database, including Microsoft SQL Server or Microsoft Access,
         change the name of the DSN in the ConnectionString, and view the page.
    -->
    <form id="form1" runat="server">

      <asp:SqlDataSource
          id="SqlDataSource1"
          runat="server"
          ProviderName="System.Data.Odbc"
          DataSourceMode="DataSet"
          ConnectionString="dsn=myodbc3dsn;"
          SelectCommand="SELECT EmployeeID,FirstName,LastName,Title FROM Employees"
          UpdateCommand="Update Employees SET FirstName=?,LastName=?,Title=? WHERE EmployeeID=?"
          OnUpdated="OnDSUpdatedHandler">
      </asp:SqlDataSource>

      <asp:GridView
          id="GridView1"
          runat="server"
          AutoGenerateColumns="False"
          DataKeyNames="EmployeeID"
          AutoGenerateEditButton="True"
          DataSourceID="SqlDataSource1">
          <columns>
              <asp:BoundField HeaderText="First Name" DataField="FirstName" />
              <asp:BoundField HeaderText="Last Name" DataField="LastName" />
              <asp:BoundField HeaderText="Title" DataField="Title" />
          </columns>
      </asp:GridView>

      <asp:Label
          id="Label1"
          runat="server">
      </asp:Label>

    </form>
  </body>
</html>

Commenti

Quando viene generato un evento, il gestore dell'evento viene richiamato tramite un delegato. Per altre informazioni su come gestire gli eventi, vedere la gestione e generazione di eventi.

Il metodo OnUpdated consente inoltre alle classi derivate di gestire l'evento senza associare un delegato. È la tecnica consigliata per la gestione dell'evento in una classe derivata.

Note per gli eredi

Quando si esegue l'override del metodo in una classe derivata, assicurarsi di chiamare il OnUpdated(SqlDataSourceStatusEventArgs)OnUpdated(SqlDataSourceStatusEventArgs) metodo per la classe base in modo che i delegati registrati ricevano l'evento.

Si applica a