jsonp只支持httpget请求。

[HttpGet]        public ResultObject SubmitOrderJsonp(string gameAccount, string callback)        {            T_DTO_CardOrder.AddOrderRequest sOrder = new T_DTO_CardOrder.AddOrderRequest();var a = SubmitOrder(sOrder);            return a;        }

Global文件处理：

GlobalConfiguration.Configuration.AddJsonpFormatter(GlobalConfiguration.Configuration.Formatters.JsonForma‌​tter, "callback");