developer/Samples/NET Standard/ParallelExtensionsExtras_Standard/Extensions/APM/WebRequestExtensions.cs

   1 //--------------------------------------------------------------------------
   2 //
   3 //  Copyright (c) Microsoft Corporation.  All rights reserved.
   4 //
   5 //  File: WebRequestExtensions.cs
   6 //
   7 //--------------------------------------------------------------------------
   8
   9 using System.IO;
  10 using System.Threading.Tasks;
  11
  12 namespace System.Net
  13 {
  14     /// <summary>Extension methods for working with WebRequest asynchronously.</summary>
  15     public static class WebRequestExtensions
  16     {
  17         /// <summary>Creates a Task that represents an asynchronous request to GetResponse.</summary>
  18         /// <param name="webRequest">The WebRequest.</param>
  19         /// <returns>A Task containing the retrieved WebResponse.</returns>
  20         public static Task<WebResponse> GetResponseAsync(this WebRequest webRequest)
  21         {
  22             if (webRequest == null) throw new ArgumentNullException("webRequest");
  23             return Task<WebResponse>.Factory.FromAsync(
  24                 webRequest.BeginGetResponse, webRequest.EndGetResponse, webRequest /* object state for debugging */);
  25         }
  26
  27         /// <summary>Creates a Task that represents an asynchronous request to GetRequestStream.</summary>
  28         /// <param name="webRequest">The WebRequest.</param>
  29         /// <returns>A Task containing the retrieved Stream.</returns>
  30         public static Task<Stream> GetRequestStreamAsync(this WebRequest webRequest)
  31         {
  32             if (webRequest == null) throw new ArgumentNullException("webRequest");
  33             return Task<Stream>.Factory.FromAsync(
  34                 webRequest.BeginGetRequestStream, webRequest.EndGetRequestStream, webRequest /* object state for debugging */);
  35         }
  36
  37         /// <summary>Creates a Task that respresents downloading all of the data from a WebRequest.</summary>
  38         /// <param name="webRequest">The WebRequest.</param>
  39         /// <returns>A Task containing the downloaded content.</returns>
  40         public static Task<byte[]> DownloadDataAsync(this WebRequest webRequest)
  41         {
  42             // Asynchronously get the response.  When that's done, asynchronously read the contents.
  43             return webRequest.GetResponseAsync().ContinueWith(response =>
  44             {
  45                 return response.Result.GetResponseStream().ReadAllBytesAsync();
  46             }).Unwrap();
  47         }
  48     }
  49 }