Cannot implicitly convert Web.Http.Results.JsonResult to Web.Mvc.JsonResult

Question

I've set up this test method on a controller to strip out any complication to it. Based off of all the results I've found from searching this should work. I'm not sure what I'm missing here.

public JsonResult test() 
{
    return Json(new { id = 1 });
}

This is the error I get.

Cannot implicitly convert type 'System.Web.Http.Results.JsonResult' to 'System.Web.Mvc.JsonResult'

Answer 1

you should return a JsonResult instead of just Json

 public JsonResult test() 
    {
        var result = new JsonResult();
        result.Data = new
        {
             id = 1
         };
        result.JsonRequestBehavior = JsonRequestBehavior.AllowGet;
        return result;
    }

Answer 2

Try the following:

public System.Web.Http.Results.JsonResult test() 
{
    return Json(new { id = 1 });
}

It seems that Json does not generate a System.Web.Mvc.JsonResult which is expected as you are probably using System.Web.Mvc; but a System.Web.Http.Results.JsonResult.
The more generic one should also work:

public ActionResult test() 
{
    return Json(new { id = 1 });
}

NOTE:
In my MVC controllers the Json method does return a System.Web.Mvc.JsonResult. Are you inheriting from the default System.Web.Mvc.Controller?

Answer 3

Try

return Json(new { id = 1 }, JsonRequestBehavior.AllowGet);

Answer 4

You need to return the data through a model class rather than an anonymous class. Like:

public System.Web.Http.Results.JsonResult<modelClass> test(){
        return Json(new modelClass(){ id=1 });
}