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DownloadDataCompletedEventArgs Class

Provides data for the DownloadDataCompleted event.

System.Object
  System.EventArgs
    System.ComponentModel.AsyncCompletedEventArgs
      System.Net.DownloadDataCompletedEventArgs

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

'Declaration
Public Class DownloadDataCompletedEventArgs _
	Inherits AsyncCompletedEventArgs

The DownloadDataCompletedEventArgs type exposes the following members.

  NameDescription
Public propertyCancelledGets a value indicating whether an asynchronous operation has been canceled. (Inherited from AsyncCompletedEventArgs.)
Public propertyErrorGets a value indicating which error occurred during an asynchronous operation. (Inherited from AsyncCompletedEventArgs.)
Public propertyResultGets the data that is downloaded by a DownloadDataAsync method.
Public propertyUserStateGets the unique identifier for the asynchronous task. (Inherited from AsyncCompletedEventArgs.)
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  NameDescription
Public methodEquals(Object)Determines whether the specified object is equal to the current object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetHashCodeServes as the default hash function. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Protected methodRaiseExceptionIfNecessaryRaises a user-supplied exception if an asynchronous operation failed. (Inherited from AsyncCompletedEventArgs.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
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Instances of this class are passed to the DownloadDataCompletedEventHandler.

The following code example demonstrates downloading a user-specified resource.

		'  Sample call : DownLoadDataInBackground ("http:' www.contoso.com/GameScores.html") 
		Public Shared Sub DownloadDataInBackground(ByVal address As String)

			Dim waiter As System.Threading.AutoResetEvent = New System.Threading.AutoResetEvent(False)
			Dim client As WebClient = New WebClient()

			'  Specify that the DownloadDataCallback method gets called 
			'  when the download completes. 
			AddHandler client.DownloadDataCompleted, AddressOf DownloadDataCallback
                        Dim uri as Uri = New Uri(address)
			client.DownloadDataAsync(uri, waiter)

			'  Block the main application thread. Real applications 
			'  can perform other tasks while waiting for the download to complete.
			waiter.WaitOne()
		End Sub

The following method is called when the download completes.

        Private Shared Sub DownloadDataCallback(ByVal sender As Object, ByVal e As DownloadDataCompletedEventArgs)

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

            Try 

                '  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 data() As Byte = CType(e.Result, Byte())
                    Dim textData As String = System.Text.Encoding.UTF8.GetString(data)

                    Console.WriteLine(textData)
                End If 
            Finally 

                '  Let the main application thread resume.
                waiter.Set()
            End Try 
        End Sub

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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