CORS in Asp.net MVC Web API v2

Step 1.

Install cors from NeGet

Step 2.

Enable cors in config

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web.Http;

namespace WebSample
{
    public static class WebApiConfig
    {
        public static void Register(HttpConfiguration config)
        {
            // Web API configuration and services

            // Web API routes
            config.MapHttpAttributeRoutes();

            config.Routes.MapHttpRoute(
                name: "DefaultApi",
                routeTemplate: "api/{controller}/{id}",
                defaults: new { id = RouteParameter.Optional }
            );

            config.EnableCors();
        }
    }
}

Step 3

Add cors attribute to your controller

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web.Http;
using System.Web.Http.Cors;
using WebSample.Models;

namespace WebSample.Controllers.Api
{
    public class JobController : ApiController
    {
        [EnableCors(origins: "*", headers: "*", methods: "GET")]
        public Message Get()
        {
            return new Message
            {
                ID = 2,
                Content = "Job"
            };
        }
    }
}

Step 4

Test x-domain request

Serialize object without null field/member in .net web api

using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Runtime.Serialization;
using System.Web.Http;

namespace WebApplication1.Controllers
{
    public class MemberController : ApiController
    {
        // GET api/member/5
        public Member Get(int id)
        {
            return new Member()
            {
                ID = id,
                FirstName = "Bruce"
            };
        }
    }

    [DataContract]
    public class Member
    {
        [DataMember]
        public int ID { get; set; }
        [DataMember(EmitDefaultValue = false)]
        [JsonProperty(NullValueHandling = NullValueHandling.Ignore)]
        public string FirstName { get; set; }
        [DataMember(EmitDefaultValue = false)]
        [JsonProperty(NullValueHandling = NullValueHandling.Ignore)]
        public string LastName { get; set; }
        [DataMember(EmitDefaultValue = false)]
        [JsonProperty(NullValueHandling = NullValueHandling.Ignore)]
        public DateTime? Birthday { get; set; }
    }
}