ASP.NET MVC: Best C# method of building a Json ActionResult

Question

Similar questions have been asked in the past, but they seem a little dated now. I'm trying to get the current general consensus on what's the best way to construct a JsonResult in ASP.NET MVC. The context of this question is to use the most current methods available from .NET 4/4.5 & MVC 4

Here's a few popular methods I've come across over the years:

var json1 = new { foo = 123, bar = "abc" };

var json2 = new Dictionary<string, object>{ { "foo", 123 }, { "bar", "abc" } };

dynamic json3;
json3.foo = 123;
json3.bar = "abc";

Please also the explain the pros/cons of your preferred method

Answer 1

Personally I use this one:

public class MyViewModel
{
    public int Foo { get; set; }
    public string Bar { get; set; }
}

and then:

public ActionResult Foo()
{
    var model = new MyViewModel
    {
        Foo = 123,
        Bar = "abc"
    };
    return Json(model, JsonRequestBehavior.AllowGet);
}

Pros:

• strong typing
• no magic strings
• refactor friendly
• unit test friendly

• the code is perfectly easily transposable to a new Web Api controller action call keeping the previous points true:

  public class ValuesController: ApiController
  {
      public MyViewModel Foo()
      {
          return new MyViewModel
          {
              Foo = 123,
              Bar = "abc"
          };
      }
  }
  

Cons: haven't encountered one yet.