DownloadStringCompletedEventHandler DownloadStringCompletedEventHandler DownloadStringCompletedEventHandler DownloadStringCompletedEventHandler Delegate

Definition

Stellt die Methode zur Behandlung des DownloadStringCompleted-Ereignisses eines WebClient-Objekts dar.Represents the method that will handle the DownloadStringCompleted event of a WebClient.

public delegate void DownloadStringCompletedEventHandler(System::Object ^ sender, DownloadStringCompletedEventArgs ^ e);
public delegate void DownloadStringCompletedEventHandler(object sender, DownloadStringCompletedEventArgs e);
type DownloadStringCompletedEventHandler = delegate of obj * DownloadStringCompletedEventArgs -> unit
Public Delegate Sub DownloadStringCompletedEventHandler(sender As Object, e As DownloadStringCompletedEventArgs)

Parameter

sender
Object Object Object Object

Die Quelle des Ereignisses.The source of the event.

Vererbung
DownloadStringCompletedEventHandlerDownloadStringCompletedEventHandlerDownloadStringCompletedEventHandlerDownloadStringCompletedEventHandler

Beispiele

Im folgenden Codebeispiel wird das asynchrone Herunterladen einer Zeichenfolge veranschaulicht.The following code example demonstrates downloading a string asynchronously.

// Sample call : DownloadStringInBackground2 ("http://www.contoso.com/GameScores.html");
void DownloadStringInBackground2( String^ address )
{
   WebClient^ client = gcnew WebClient;
   Uri ^uri = gcnew Uri(address);
   
   // Specify that the DownloadStringCallback2 method gets called
   // when the download completes.
   client->DownloadStringCompleted += gcnew DownloadStringCompletedEventHandler( DownloadStringCallback2 );
   client->DownloadStringAsync( uri );
}


// Sample call : DownloadStringInBackground2 ("http://www.contoso.com/GameScores.html");
public static void DownloadStringInBackground2 (string address)
{
    WebClient client = new WebClient ();
    Uri uri = new Uri(address);

    // Specify that the DownloadStringCallback2 method gets called
    // when the download completes.
    client.DownloadStringCompleted += new DownloadStringCompletedEventHandler (DownloadStringCallback2);
    client.DownloadStringAsync (uri);
}

'  Sample call : DownloadStringInBackground2 ("http:' www.contoso.com/GameScores.html")
Public Shared Sub DownloadStringInBackground2(ByVal address As String)

	Dim client As WebClient = New WebClient()

	'  Specify that the DownloadStringCallback2 method gets called
	'  when the download completes.
	AddHandler client.DownloadStringCompleted, AddressOf DownloadStringCallback2
                      Dim uri as Uri = New Uri(address)
	client.DownloadStringAsync(uri)
End Sub

Die folgende Methode wird aufgerufen, wenn der Download abgeschlossen ist.The following method is called when the download completes.

void DownloadStringCallback2( Object^ /*sender*/, DownloadStringCompletedEventArgs^ e )
{
   
   // If the request was not canceled and did not throw
   // an exception, display the resource.
   if (  !e->Cancelled && e->Error == nullptr )
   {
      String^ textString = dynamic_cast<String^>(e->Result);
      Console::WriteLine( textString );
   }
}


private static void DownloadStringCallback2 (Object sender, DownloadStringCompletedEventArgs e)
{
    // If the request was not canceled and did not throw
    // an exception, display the resource.
    if (!e.Cancelled && e.Error == null)
    {
        string textString = (string)e.Result;

        Console.WriteLine (textString);
    }
}

Private Shared Sub DownloadStringCallback2(ByVal sender As Object, ByVal e As DownloadStringCompletedEventArgs)

    '  If the request was not canceled and did not throw
    '  an exception, display the resource.
    If e.Cancelled = False AndAlso e.Error Is Nothing Then

        Dim textString As String = CStr(e.Result)
        Console.WriteLine(textString)
    End If
End Sub

Hinweise

Beim Erstellen eines DownloadStringCompletedEventHandler-Delegaten bestimmen Sie die Methode für die Ereignisbehandlung.When you create a DownloadStringCompletedEventHandler delegate, you identify the method that will handle the event. Um dem Ereignishandler das Ereignis zuzuordnen, fügen Sie dem Ereignis eine Instanz des Delegaten hinzu.To associate the event with your event handler, add an instance of the delegate to the event. Der Ereignishandler wird bei jedem Eintreten des Ereignisses aufgerufen, sofern der Delegat nicht entfernt wird.The event handler is called whenever the event occurs, unless you remove the delegate. Weitere Informationen zu Ereignishandlerdelegaten finden Sie unter behandeln und Auswerfen von Ereignissen.For more information about event handler delegates, see Handling and Raising Events.

Erweiterungsmethoden

GetMethodInfo(Delegate) GetMethodInfo(Delegate) GetMethodInfo(Delegate) GetMethodInfo(Delegate)

Ruft ein Objekt ab, das die Methode darstellt, die vom angegebenen Delegaten dargestellt wird.Gets an object that represents the method represented by the specified delegate.

Gilt für: