OpenWriteCompletedEventHandler Delegate

 

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

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

Public Delegate Sub OpenWriteCompletedEventHandler (
	sender As Object,
	e As OpenWriteCompletedEventArgs
)

Parameters

sender
Type: System.Object

The source of the event.

e
Type: System.Net.OpenWriteCompletedEventArgs

A OpenWriteCompletedEventArgs containing event data.

When you create a OpenWriteCompletedEventHandler 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.

The following code example demonstrates opening a stream to write data to be uploaded.

Public Shared Sub OpenResourceForPosting(ByVal address As String)

	Dim client As WebClient = New WebClient()
	'  Specify that the OpenWriteCallback method gets called
	'  when the writeable stream is available.
	AddHandler client.OpenWriteCompleted, AddressOf OpenWriteCallback2
                      Dim uri as Uri = New Uri(address)
	client.OpenWriteAsync(uri)
	'  Applications can perform other tasks
	'  while waiting for the upload to complete.
End Sub

The following method is called when the stream is available.

Private Shared Sub OpenWriteCallback2(ByVal sender As Object, ByVal e As OpenWriteCompletedEventArgs)

    Dim body As Stream = Nothing
    Dim s As StreamWriter = Nothing

    Try

        body = CType(e.Result, Stream)
        s = New StreamWriter(body)
        s.AutoFlush = True
        s.Write("This is content data to be sent to the server.")
    Finally

        If Not s Is Nothing Then

            s.Close()
        End If

        If Not body Is Nothing Then

            body.Close()
        End If
    End Try
End Sub

.NET Framework
Available since 2.0
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
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