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OpenReadCompletedEventHandler Delegate
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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)

public delegate void OpenReadCompletedEventHandler(
	Object^ sender, 
	OpenReadCompletedEventArgs^ e


Type: System::Object

The source of the event.

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.

void OpenResourceForReading2( String^ address )
   WebClient^ client = gcnew WebClient;
   Uri ^uri = gcnew Uri(address);

   client->OpenReadCompleted += gcnew OpenReadCompletedEventHandler( OpenReadCallback2 );
   client->OpenReadAsync( uri );

The following method is called when the download completes.

void OpenReadCallback2( Object^ /*sender*/, OpenReadCompletedEventArgs^ e )
   Stream^ reply = nullptr;
   StreamReader^ s = nullptr;
      reply = dynamic_cast<Stream^>(e->Result);
      s = gcnew StreamReader( reply );
      Console::WriteLine( s->ReadToEnd() );
      if ( s != nullptr )
      if ( reply != nullptr )


.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

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8
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