DownloadDataCompletedEventHandler 대리자

정의

네임스페이스:

System.Net

어셈블리:

netstandard.dll, System.Net.WebClient.dll

Source:

WebClient.cs

의 이벤트를 처리할 메서드를 DownloadDataCompletedWebClient나타냅니다.

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

이벤트의 출처입니다.

e

DownloadDataCompletedEventArgs

DownloadDataCompletedEventArgs 포함된 이벤트 데이터입니다.

예제

다음 코드 예제에서는 사용자 지정 리소스를 다운로드하는 방법을 보여 줍니다.

// 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

다운로드가 완료되면 다음 메서드가 호출됩니다.

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

대리자를 DownloadDataCompletedEventHandler 만들 때 이벤트를 처리할 메서드를 식별합니다. 이벤트를 이벤트 처리기와 연결하려면 대리자의 인스턴스를 이벤트에 추가합니다. 대리자를 제거하지 않는 한 이벤트가 발생할 때마다 이벤트 처리기가 호출됩니다. 이벤트 처리기 대리자에 대한 자세한 내용은 이벤트 처리 및 발생을 참조하세요.

확장명 메서드

Name	Description
GetMethodInfo(Delegate)	지정된 대리자가 나타내는 메서드를 나타내는 개체를 가져옵니다.