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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)
/** @delegate */
public delegate void OpenReadCompletedEventHandler (
	Object sender, 
	OpenReadCompletedEventArgs e
)
Not applicable.

Parameters

sender

The source of the event.

e

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


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


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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