How to use HttpWebRequest (.NET) asynchronously?

Question

How can I use HttpWebRequest (.NET, C#) asynchronously?

Answer 1

.NET has changed since many of these answers were posted, and I'd like to provide a more up-to-date answer. Use an async method to start a Task that will run on a background thread:

private async Task MakeRequestAsync(String url)
{    
    String responseText = await Task.Run(() =>
    {
        try
        {
            HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
            WebResponse response = request.GetResponse();            
            Stream responseStream = response.GetResponseStream();
            return new StreamReader(responseStream).ReadToEnd();            
        }
        catch (Exception e)
        {
            Console.WriteLine("Error: " + e.Message);
        }
        return null;
    });

    return responseText;
}

To use the async method:

String response = await MakeRequestAsync("http://example.com/");

Update:

This solution does not work for UWP apps which use WebRequest.GetResponseAsync() instead of WebRequest.GetResponse(), and it does not call the Dispose() methods where appropriate. @dragansr has a good alternative solution that addresses these issues.