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UploadFileCompletedEventHandler Delegate

Represents the method that will handle the UploadFileCompleted event of a WebClient.

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

'Declaration
Public Delegate Sub UploadFileCompletedEventHandler ( _
	sender As Object, _
	e As UploadFileCompletedEventArgs _
)
'Usage
Dim instance As New UploadFileCompletedEventHandler(AddressOf HandlerMethod)
/** @delegate */
public delegate void UploadFileCompletedEventHandler (
	Object sender, 
	UploadFileCompletedEventArgs e
)
Not applicable.

Parameters

sender

The source of the event.

e

A UploadFileCompletedEventArgs that contains event data.

When you create a UploadFileCompletedEventHandler delegate, you identify the method that will handle the event. To associate the event with your event handler, add an instance of the delegate to the event. The event handler is called whenever the event occurs, unless you remove the delegate. For more information about event handler delegates, see Events and Delegates.

The following code example demonstrates asynchronously uploading a file.

'  Sample call: UploadFileInBackground("http:' www.contoso.com/fileUpload.aspx", "data.txt")
Public Shared Sub UploadFileInBackground(ByVal address As String, ByVal fileName As String)

    Dim waiter As System.Threading.AutoResetEvent = New System.Threading.AutoResetEvent(False)
    Dim client As WebClient = New WebClient()
    Dim method As String = "POST"
                 Dim uri as Uri =  New Uri(address)

    '  Specify that that UploadFileCallback method gets called
    '  when the file upload completes.
    AddHandler client.UploadFileCompleted, AddressOf UploadFileCallback
    client.UploadFileAsync(uri, method, fileName, waiter)

    '  Block the main application thread. Real applications
    '  can perform other tasks while waiting for the upload to complete.
    waiter.WaitOne()
    Console.WriteLine("File upload is complete.")
End Sub


The following method is called when the upload completes.

Private Shared Sub UploadFileCallback(ByVal sender As Object, ByVal e As System.Net.UploadFileCompletedEventArgs)

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

        Dim reply As String = System.Text.Encoding.UTF8.GetString(e.Result)
        Console.WriteLine(reply)
    Finally
        '  If this thread throws an exception, make sure that
        '  you let the main application thread resume.
        waiter.Set()
    End Try
End Sub


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

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0

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