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DownloadDataCompletedEventArgs Class
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DownloadDataCompletedEventArgs Class

Provides data for the DownloadDataCompleted event.

Namespace:  System.Net
Assembly:  System (in System.dll)

Public Class DownloadDataCompletedEventArgs _
	Inherits AsyncCompletedEventArgs
Dim instance As DownloadDataCompletedEventArgs

Instances of this class are passed to the DownloadDataCompletedEventHandler.

The following code example demonstrates downloading a user-specified resource.

		'  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.
		End Sub
// Sample call : DownLoadDataInBackground ("http://www.contoso.com/GameScores.html");
void DownloadDataInBackground (String* address)
    System::Threading::AutoResetEvent* waiter = new System::Threading::AutoResetEvent (false);
    WebClient* client = new WebClient ();

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

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

The following method is called when the download completes.

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

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


        '  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)

        End If 

        '  Let the main application thread resume.
    End Try 
End Sub
void DownloadDataCallback (Object* /*sender*/, DownloadDataCompletedEventArgs* e)
    System::Threading::AutoResetEvent* waiter = dynamic_cast<System::Threading::AutoResetEvent*>(e->UserToken);

        // If the request was not canceled and did not throw
        // an exception, display the resource.
        if (!e->Cancelled && e->Error == 0)
            Byte data[] = dynamic_cast<Byte[]>(e->Result);
            String* textData = System::Text::Encoding::UTF8->GetString (data);

            Console::WriteLine (textData);
        // Let the main application thread resume.
        waiter->Set ();


Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0

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