web api is not displaying data

public class CategoryController : ApiController
    {
        List<category> category;

        public class DataResult
        {
            public List<category> Category { get; set; }
        }

        #region Categories
        public DataResult GetCategories()
        {
            DataResult result = new DataResult();
            
            try
            {
                using (MyDB db = new MyDB())
                {
                    category = db.Category.OrderBy(c => c.Name).ToList();

                }
                if (category == null)
                {
                    throw new HttpResponseException(
                           Request.CreateResponse(HttpStatusCode.NotFound));
                }
                else
                {
                    result.Category = category;
                   
                    return result;
                }

            }
            catch (Exception ex)
            {
                throw ex;
            }
        }
        #endregion
    }

$.ajax({
       url: "/api/Category",
       type: "GET",
       dataType: 'json',
       success: function (data) {
           alert('hai');
       },
       error: function (err) {
           document.write(data);
       }
   });