asp.net web api list of list pass into json ajax

Question

I have web api controller where I try to do something like this:

public IHttpActionResult Get()
{

    var Rooms = db.Rooms.Select(r => new {
        Id = r.Id,
        Name = r.Name,
        ChairNum = r.СhairNum,
        Requests = r.Requests.ToList()
    }).ToList();

   return Ok(new { results = Rooms });

}

In Model I have this:

public partial class Room
{
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
    public Room()
    {
        this.Requests = new HashSet<Request>();
    }

    public int Id { get; set; }
    public string Name { get; set; }
    public int СhairNum { get; set; }
    public bool IsProjector { get; set; }
    public bool IsBoard { get; set; }
    public string Description { get; set; }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<Request> Requests { get; set; }
}

I tried to pass this data in service. But I have serialization error, when I call http://localhost:99999/api/Rest.

<ExceptionMessage>
The "ObjectContent`1" type could not serialize the response text for the content type "application / json; charset = utf-8".
</ ExceptionMessage>

What is the best way to pass the data like in model into json?

What do you mean you have a serialization error? What error? What line of code does it come from? — mason, Oct 31 '17 at 16:40
If I delete Requests = r.Requests.ToList() from the example there are no errors — tmf, Oct 31 '17 at 16:45
The answers here might be helpful: https://stackoverflow.com/questions/13959048/asp-net-web-api-error-the-objectcontent1-type-failed-to-serialize-the-respon — Luke T Brooks, Oct 31 '17 at 17:04

tmf · Accepted Answer · 2017-11-01T06:50:03.370

1

It helped to put in WebApiConfig:

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

edited Nov 01 '17 at 06:50

answered Oct 31 '17 at 18:58

tmf

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asp.net web api list of list pass into json ajax

1 Answers1