Why Json() Function is unknown

问题:

I have the following code (in MVC3):

    public JsonResult GetTown(string term)
    {
        db = new SHAMUTEntities1();

            var data = db.towns.Where(t => t.name.Contains(term))
                .Take(10)
                .Select(t => new {label=t.name }).ToArray();

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

I get the following error:

System.Web.Helper.Json is a type but is used like a variable

Can anybody help with this. thanks

回答1:

Json is a method of the System.Web.Mvc.Controller class of ASP.NET MVC 3. Since it's not compiling, you are probably using it in a class that does not derived from Controller.

To fix it, just return the data instance from your method and convert it to JSON in a controller metod.