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OpenReadCompletedEventHandler Delegate

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

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

'Declaration
Public Delegate Sub OpenReadCompletedEventHandler ( _
	sender As Object, _
	e As OpenReadCompletedEventArgs _
)
'Usage
Dim instance As New OpenReadCompletedEventHandler(AddressOf HandlerMethod)

Parameters

sender
Type: System.Object

The source of the event.

e
Type: System.Net.OpenReadCompletedEventArgs

A OpenReadCompletedEventArgs containing event data.

When you create a OpenReadCompletedEventHandler 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 downloading a resource for reading.

		Public Shared Sub OpenResourceForReading2(ByVal address As String)

			Dim client As WebClient = New WebClient()
			AddHandler client.OpenReadCompleted, AddressOf OpenReadCallback2
                        Dim uri as Uri = New Uri(address)
			client.OpenReadAsync(uri)                        
		End Sub
void OpenResourceForReading2 (String* address)
{
    WebClient* client = new WebClient ();
    client->OpenReadCompleted += new OpenReadCompletedEventHandler (OpenReadCallback2);
    client->OpenReadAsync (address);
}

The following method is called when the download completes.

Private Shared Sub OpenReadCallback2(ByVal sender As Object, ByVal e As OpenReadCompletedEventArgs)

    Dim reply As Stream = Nothing 
    Dim s As StreamReader = Nothing 

    Try

        reply = CType(e.Result, Stream)
        s = New StreamReader(reply)
        Console.WriteLine(s.ReadToEnd())
    Finally 

        If Not s Is Nothing Then

            s.Close()
        End If 

        If Not reply Is Nothing Then

            reply.Close()
        End If 
    End Try 
End Sub
void OpenReadCallback2 (Object* /*sender*/, OpenReadCompletedEventArgs* e)
{
    Stream* reply = 0;
    StreamReader* s = 0;

    try
    {
        reply = dynamic_cast<Stream*>(e->Result);
        s = new StreamReader (reply);
        Console::WriteLine (s->ReadToEnd ());
    }
    __finally
    {
        if (s != 0)
        {
            s->Close ();
        }

        if (reply != 0)
        {
            reply->Close ();
        }
    }
}

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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