Q:

ASP.NET Core - The name 'JsonRequestBehavior' does not exist in the current context

In my ASP.NET Core (.NET Framework) project, I'm getting above error on my following Controller Action method. What I may be missing? Or, are there any work arounds?:
    public class ClientController : Controller
    {
      public ActionResult CountryLookup()
      {
        var countries = new List<SearchTypeAheadEntity>
            {
                new SearchTypeAheadEntity {ShortCode = "US", Name = "United States"},
                new SearchTypeAheadEntity {ShortCode = "CA", Name = "Canada}
            };

        return Json(countries, JsonRequestBehavior.AllowGet);
      }
    }

UPDATE: 
Please note folowing comments from  @NateBarbettini below:

JsonRequestBehavior has been deprecated in ASP.NET Core 1.0.
In accepted response from @Miguel below, the return type of action method does not specifically need to be of type JsonResult. ActionResult or IActionResult works too.

A:

Returning Json-formatted data:
public class ClientController : Controller
{
    public JsonResult CountryLookup()
    {
         var countries = new List<SearchTypeAheadEntity>
         {
             new SearchTypeAheadEntity {ShortCode = "US", Name = "United States"},
             new SearchTypeAheadEntity {ShortCode = "CA", Name = "Canada}
         };

         return Json(countries);
    }
}

A:

some times you need to return a message back in json ,simply use the json result as below , no need for jsonrequestbehavior any more ,below simple code to use 
public ActionResult DeleteSelected([FromBody]List<string> ids)
    {
        try
        {
            if (ids != null && ids.Count > 0)
            {
                foreach (var id in ids)
                {
                    bool done = new tblCodesVM().Delete(Convert.ToInt32(id));

                }
                return Json(new { success = true, responseText = "Deleted Scussefully" });

            }
            return Json(new { success = false, responseText = "Nothing Selected" });
        }
        catch (Exception dex)
        {

            return Json(new { success = false, responseText = dex.Message });
        }
    }

A:

In Code it's replace To JsonRequestBehavior.AllowGet with new Newtonsoft.Json.JsonSerializerSettings()
It's Work same as JsonRequestBehavior.AllowGet
public class ClientController : Controller
{
  public ActionResult CountryLookup()
  {
    var countries = new List<SearchTypeAheadEntity>
        {
            new SearchTypeAheadEntity {ShortCode = "US", Name = "United States"},
            new SearchTypeAheadEntity {ShortCode = "CA", Name = "Canada}
        };

    return Json(countries, new Newtonsoft.Json.JsonSerializerSettings());
  }
}

