title: Is there an automated mechanism where I can detect if any email field is missing?
body: <p>Let's assume this class:</p>
  
  <pre><code>public class AccountInfo
  {
      public string   Email;
      public string   Username;
      public string   Password;
  }
  </code></pre>
  
  <p>and this ASP api:</p>
  
  <pre><code>[HttpPost, Route("create")]
  public IActionResult CreateUser([FromBody]AccountInfo Info)
  {
      ...
  }
  </code></pre>
  
  <p>If a user passes something like this:</p>
  
  <pre><code>{
      "eail" : "ndienw",    &lt;--- notice the mispelling
      "username" : "djiw",
      "password" : "dow"
  }
  </code></pre>
  
  <p>The email field will be null, so I need in each call to check for every fields.</p>
  
  <p>Is there an automated mechanism where I can detect if any field is missing? I'm looking for something generic that can be applied through all calls.
  Being able to opt out and mark some parameters optional would be great, but in our case, everything is always needed so far.</p>
  
  <p>In this scenario, the ModelState is still valid; is that the expected behavior?</p>