DownloadDataCompletedEventHandler DownloadDataCompletedEventHandler DownloadDataCompletedEventHandler DownloadDataCompletedEventHandler Delegate

정의

DownloadDataCompletedWebClient 이벤트를 처리할 메서드를 나타냅니다.Represents the method that will handle the DownloadDataCompleted event of a WebClient.

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

매개 변수

sender
Object Object Object Object

이벤트 소스입니다.The source of the event.

상속
DownloadDataCompletedEventHandlerDownloadDataCompletedEventHandlerDownloadDataCompletedEventHandlerDownloadDataCompletedEventHandler

예제

다음 코드 예제에서는 사용자 지정 리소스를 다운로드 하는 방법을 보여 줍니다.The following code example demonstrates downloading a user-specified resource.

// Sample call : DownLoadDataInBackground ("http://www.contoso.com/GameScores.html");
void DownloadDataInBackground( String^ address )
{
   System::Threading::AutoResetEvent^ waiter = gcnew System::Threading::AutoResetEvent( false );
   WebClient^ client = gcnew WebClient;
   Uri ^uri = gcnew Uri(address);
   
   // Specify that the DownloadDataCallback method gets called
   // when the download completes.
   client->DownloadDataCompleted += gcnew DownloadDataCompletedEventHandler( DownloadDataCallback );
   client->DownloadDataAsync( uri, waiter );
   
   // Block the main application thread. Real applications
   // can perform other tasks while waiting for the download to complete.
   waiter->WaitOne();
}


// Sample call : DownLoadDataInBackground ("http://www.contoso.com/GameScores.html");
public static void DownloadDataInBackground (string address)
{
    System.Threading.AutoResetEvent waiter = new System.Threading.AutoResetEvent (false);
    WebClient client = new WebClient ();
    Uri uri = new Uri(address);

    // Specify that the DownloadDataCallback method gets called
    // when the download completes.
    client.DownloadDataCompleted += new DownloadDataCompletedEventHandler (DownloadDataCallback);
    client.DownloadDataAsync (uri, waiter);

    // Block the main application thread. Real applications
    // can perform other tasks while waiting for the download to complete.
    waiter.WaitOne ();
}

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

    Dim waiter As System.Threading.AutoResetEvent = New System.Threading.AutoResetEvent(False)
    Dim client As WebClient = New WebClient()

    '  Specify that the DownloadDataCallback method gets called
    '  when the download completes.
    AddHandler client.DownloadDataCompleted, AddressOf DownloadDataCallback
                Dim uri as Uri = New Uri(address)
    client.DownloadDataAsync(uri, waiter)

    '  Block the main application thread. Real applications
    '  can perform other tasks while waiting for the download to complete.
    waiter.WaitOne()
End Sub

다음 메서드는 다운로드가 완료 되 면 호출 됩니다.The following method is called when the download completes.

void DownloadDataCallback( Object^ /*sender*/, DownloadDataCompletedEventArgs^ e )
{
   System::Threading::AutoResetEvent^ waiter = dynamic_cast<System::Threading::AutoResetEvent^>(e->UserState);
   try
   {
      
      // If the request was not canceled and did not throw
      // an exception, display the resource.
      if (  !e->Cancelled && e->Error == nullptr )
      {
         array<Byte>^data = dynamic_cast<array<Byte>^>(e->Result);
         String^ textData = System::Text::Encoding::UTF8->GetString( data );
         Console::WriteLine( textData );
      }
   }
   finally
   {
      
      // Let the main application thread resume.
      waiter->Set();
   }

}


private static void DownloadDataCallback (Object sender, DownloadDataCompletedEventArgs e)
{
    System.Threading.AutoResetEvent waiter = (System.Threading.AutoResetEvent)e.UserState;

    try
    {
        // If the request was not canceled and did not throw
        // an exception, display the resource.
        if (!e.Cancelled && e.Error == null)
        {
            byte[] data = (byte[])e.Result;
            string textData = System.Text.Encoding.UTF8.GetString (data);

            Console.WriteLine (textData);
        }
    }
    finally
    {
        // Let the main application thread resume.
        waiter.Set ();
    }
}

Private Shared Sub DownloadDataCallback(ByVal sender As Object, ByVal e As DownloadDataCompletedEventArgs)

    Dim waiter As System.Threading.AutoResetEvent = CType(e.UserState, System.Threading.AutoResetEvent)

    Try

        '  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 data() As Byte = CType(e.Result, Byte())
            Dim textData As String = System.Text.Encoding.UTF8.GetString(data)

            Console.WriteLine(textData)
        End If
    Finally

        '  Let the main application thread resume.
        waiter.Set()
    End Try
End Sub

설명

DownloadDataCompletedEventHandler 대리자를 만들 때, 이벤트를 처리할 메서드를 식별합니다.When you create a DownloadDataCompletedEventHandler delegate, you identify the method that will handle the event. 이벤트를 이벤트 처리기와 연결하려면 대리자의 인스턴스를 해당 이벤트에 추가합니다.To associate the event with your event handler, add an instance of the delegate to the event. 대리자를 제거하지 않는 경우 이벤트가 발생할 때마다 이벤트 처리기가 호출됩니다.The event handler is called whenever the event occurs, unless you remove the delegate. 이벤트 처리기 대리자에 대 한 자세한 내용은 참조 하세요. 이벤트 처리 및 발생합니다.For more information about event handler delegates, see Handling and Raising Events.

확장 메서드

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

지정된 대리자가 나타내는 메서드를 나타내는 개체를 가져옵니다.Gets an object that represents the method represented by the specified delegate.

적용 대상