title: HttpClient post async form-url-encoded and string content not working
body: <p>I am trying to use System.Net.Http.HttpClient PostAsync method to make an api call. It hangs forever after await _httpClient.PostAsync(requestUri, stringContent);</p>
  
  <p>HttpClient configuration : </p>
  
  <pre><code>_httpClient = new System.Net.Http.HttpClient(new HttpClientHandler
              {
                  UseDefaultCredentials = WithDefaultCredentials,
                  AllowAutoRedirect = false
              });
  
  _httpClient.DefaultRequestHeaders.Accept.Clear();
  _httpClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue(APPLICATION_JSON));
  _httpClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue(ApplicationXWwwFormUrlencoded));
  if (!string.IsNullOrEmpty(CultureInfo.CurrentUICulture.Name))
  {
       _httpClient.DefaultRequestHeaders.AcceptLanguage.Add(new 
       StringWithQualityHeaderValue(CultureInfo.CurrentUICulture.Name));
  }
  </code></pre>
  
  <p>PostAsync call : </p>
  
  <pre><code>var stringContent = new StringContent(content);
  stringContent.Headers.ContentType = MediaTypeHeaderValue.Parse("application/x-www-form-urlencoded");
  var response = await _httpClient.PostAsync(requestUri, stringContent);
  var responseContent = await response.Content.ReadAsStringAsync();
  </code></pre>