DownloadStringCompletedEventHandler Delegate
Assembly: System (in system.dll)
'Declaration Public Delegate Sub DownloadStringCompletedEventHandler ( _ sender As Object, _ e As DownloadStringCompletedEventArgs _ ) 'Usage Dim instance As New DownloadStringCompletedEventHandler(AddressOf HandlerMethod)
/** @delegate */ public delegate void DownloadStringCompletedEventHandler ( Object sender, DownloadStringCompletedEventArgs e )
JScript supports the use of delegates, but not the declaration of new ones.
Parameters
- sender
The source of the event.
- e
A DownloadStringCompletedEventArgs that contains event data.
When you create a DownloadStringCompletedEventHandler 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 downloading a string asynchronously.
' Sample call : DownloadStringInBackground2 ("http:' www.contoso.com/GameScores.html") Public Shared Sub DownloadStringInBackground2(ByVal address As String) Dim client As WebClient = New WebClient() ' Specify that the DownloadStringCallback2 method gets called ' when the download completes. AddHandler client.DownloadStringCompleted, AddressOf DownloadStringCallback2 Dim uri as Uri = New Uri(address) client.DownloadStringAsync(uri) End Sub
The following method is called when the download completes.
Public Shared Sub DownloadStringCallback2(ByVal sender As Object, ByVal e As DownloadStringCompletedEventArgs) ' 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 textString As String = CStr(e.Result) Console.WriteLine(textString) End If End Sub
Windows 98, Windows 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 .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.