title: Postman Testing send string to Web Api accepting string is null
body: <p>I have been testing all the Get,Create,Update methods with Postman in which the Get passes in nothing.   The Create and Update passes in raw  json with Activity object with several properties that do match up with the C# class</p>
  
  <p>So this signature for Create and Update works fine</p>
  
  <pre><code>[HttpPost]
  public IHttpActionResult UpdateActivity(Activity activity)
  </code></pre>
  
  <p>Above works with Postman passing in JSON content type with all the properties.  I have done this on OTHER projects.</p>
  
  <p><strong>HOWEVER</strong></p>
  
  <p>I'm trying to simply pass in a <strong>string</strong> and it is null no matter what</p>
  
  <pre><code>public IHttpActionResult DeleteActivity([FromBody]string Id)
  {
      // delete
      var del = ActivityService.DeleteActivity(Id);
      return Ok(del);
  }
  </code></pre>
  
  <p>Postman I tried MANY ways </p>
  
  <pre><code>http://localhost:49810/api/activityapi/deleteactivity
  </code></pre>
  
  <p>I have tried MANY many ways based on blogs and google search one such example</p>
  
  <pre><code>{ "Id" = "5808786fa3e9ec79546b3c71" } 
  </code></pre>