Asp.net web api Web API序列化/反序列化派生类型

我有一个Web API，它返回一个对象列表，当客户端传递Accept application/json时，我希望我的全局注册json格式化程序在序列化过程中包含派生类型的TypeNameHandling。然而这不起作用，我不明白为什么这不起作用

我的对象

public class BaseClass 
{
    public int Id { get; set; }
}

public class SubClass : BaseClass
{
    public string SubClassProp { get; set; }
}

public class SubClassA : SubClass
{
    public string SubClassAProp { get; set; }
}

public class SubClassB : SubClass
{
   public string SubClassBProp { get; set; }
}

public static void Register(HttpConfiguration config) 
{
   var formatters = GlobalConfiguration.Configuration.Formatters;
   var jsonFormatter = formatters.JsonFormatter;
   var settings = jsonFormatter.SerializerSettings;
   settings.Formatting = Formatting.Indented;
   settings.NullValueHandling = NullValueHandling.Ignore;
   settings.TypeNameHandling = TypeNameHandling.Auto;
}

WebApiConfig

public class BaseClass 
{
    public int Id { get; set; }
}

public class SubClass : BaseClass
{
    public string SubClassProp { get; set; }
}

public class SubClassA : SubClass
{
    public string SubClassAProp { get; set; }
}

public class SubClassB : SubClass
{
   public string SubClassBProp { get; set; }
}

public static void Register(HttpConfiguration config) 
{
   var formatters = GlobalConfiguration.Configuration.Formatters;
   var jsonFormatter = formatters.JsonFormatter;
   var settings = jsonFormatter.SerializerSettings;
   settings.Formatting = Formatting.Indented;
   settings.NullValueHandling = NullValueHandling.Ignore;
   settings.TypeNameHandling = TypeNameHandling.Auto;
}

Web API控制器

public class MyController : ApiController
{
    [HttpGet]
    public async Task<IList<BaseClass>> GetClasses() 
    {
       return new List<BaseClass>
              {
                 new SubClassA 
                 { 
                    Id = 1, 
                    SubClassProp = "SubClass", 
                    SubClassAProp = "SubClassAProp"
                 },
                 new SubClassB
                 {
                    Id = 2, 
                    SubClassProp = "SubClass", 
                    SubClassBProp = "SubClassBProp"
                 }
              };
    }
}

公共类MyController:ApiController
{
[HttpGet]
公共异步任务GetClasses（）
{
返回新列表
{
新亚纲
{ 
Id=1，
SubClassProp=“SubClass”，
subassaprop=“subassaprop”
},
新亚类B
{
Id=2，
SubClassProp=“SubClass”，
SubClassBProp=“SubClassBProp”
}
};
}
}

来自同一解决方案中API客户端的调用

var client = new HttpClient() { BaseAddress = new Uri("uri goes here...")}
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

var resp = await client.GetAsync("uri goes here..."));
var jsonContent = await resp.Content.ReadAsStringAsync();

var ListOfClasses = JsonConvert.DeserializeObject<IList<BaseClass>>(jsonContent, new JsonSerializerSettings { TypeNameHandling = TypeNameHandling.Auto });

var-client=new-HttpClient（）{BaseAddress=new-Uri（“Uri在这里…”）}
client.DefaultRequestHeaders.Accept.Clear（）；
client.DefaultRequestHeaders.Accept.Add（新的MediaTypeWithQualityHeaderValue（“应用程序/json”）；
var resp=await client.GetAsync（“uri在这里…”）；
var jsonContent=await resp.Content.ReadAsStringAsync（）；
var ListOfClasses=JsonConvert.DeserializeObject（jsonContent，新的JsonSerializerSettings{TypeNameHandling=TypeNameHandling.Auto}）；

我希望得到一个元素，它是subassa，另一个是subassb，但两者都是基类

我还希望能够在Post方法中将json反序列化为对象

---

这对于json和xml都是可能的

字符串的内容是什么？