title: WebAPI Selfhost: Can't bind multiple parameters to the request's content
body: <p>The below code are simplified to show the necessity. May I know what is wrong? I can't seems to retrieve two Parameters (A and B in this case) using the [FromBody] attribute.</p>
  
  <p>The error message is "Can't bind multiple parameters ('A' and 'B') to the request's content"</p>
  
  <p>It is perfectly fine if I have either A or B only.</p>
  
  <p>Web API:</p>
  
  <pre><code>[Route("API/Test"), HttpPost]
  public IHttpActionResult Test([FromBody] int A, [FromBody] int B)
  </code></pre>
  
  <p>Client:</p>
  
  <pre><code>HttpClient client = new HttpClient();
  var content = new FormUrlEncodedContent(
      new Dictionary&lt;string, string&gt; {
          { "A", "123" },
          { "B", "456" }
      });
  client.PostAsync("http://localhost/API/Test", content).Result;
  </code></pre>