ASP.NET WEB API序列化：最佳实践

Question

I have a ASP.NET WEB API v2 project with entity framework and when i call the route

// GET api/People

i have a json serialization error.

So, i have a People entity:

public People()
{
   public int Id { get; set; }
   public string Name{ get; set; }
   ....
   ....
   public virtual ICollection<Role> Role{ get; set; }
   public virtual ICollection<Device> Device { get; set; }
}

and the controller:

// GET api/People
public IEnumerable<People> GetPeople()
{
    var p = db.People.ToList<People>().ToList();
    return p;
}

and, in debug, p count 7 elements and it's correct but i have an error in serialization. I think the problem is the loading of the collection.

In WebApiConfig.cs i've put this code:

var json = config.Formatters.JsonFormatter;
json.SerializerSettings.PreserveReferencesHandling= Newtonsoft.Json.PreserveReferencesHandling.Objects;
config.Formatters.Remove(config.Formatters.XmlFormatter);

So what's the best practice in web api to serialize a complex entity? I must return an anonymous type instead of the entire People object?

The error is:

{"$id":"1","Message":"An error has occurred.","ExceptionMessage":"The 'ObjectContent`1' type failed to serialize the response body for content type 'application/json; charset=utf-8'.","ExceptionType":"System.InvalidOperationException","StackTrace":null,"InnerException":{"$id":"2","Message":"An error has occurred.","ExceptionMessage":"Error getting value from 'Tessera' on 'System.Data.Entity.DynamicProxies.Tag_0E0771BC33ADE7B095FF6A8E8DC8501A7DB9907E6F3C703A4EDC71C83D881122'.","ExceptionType":"Newtonsoft.Json.JsonSerializationException","StackTrace":"   in Newtonsoft.Json.Seria.......

Answer 1

this will return json by default, unless you specify text/xml as request accept header

var appXmlType = config.Formatters.XmlFormatter.SupportedMediaTypes.FirstOrDefault(t => t.MediaType == "application/xml");
config.Formatters.XmlFormatter.SupportedMediaTypes.Remove(appXmlType);