title: c# web api derived type is not serialised
body: <p>I have a requirement to store various types of fields in Db. I have base field class with all common property and I have derived classes with specific properties for each field type.</p>
  <pre><code>public class BaseField
  {
     public string ID{get;set;}
     public string Name{get;set;}
  }
  
  public class CheckboxField:BaseField
  {
     public bool Checked{get;set;}
  }
  </code></pre>
  <p>I have an asp.net core web API method that accepts BaseField as a parameter. When I try to save an object of type CheckboxField it is always converted BaseField. I know that as the parameter is of type BaseField, it is always serializing to BaseField but I want to know how can I handle saving checkbox field using the same method.</p>