c# 【MVC】WebApi设置返回Json

        public static HttpResponseMessage toJson(Object obj)
        {
            String str;
            if (obj is String || obj is Char)
            {
                str = obj.ToString();
            }
            else
            {
                JavaScriptSerializer serializer = new JavaScriptSerializer();
                str = serializer.Serialize(obj);
            }
            HttpResponseMessage result = new HttpResponseMessage { Content = new StringContent(str, Encoding.GetEncoding("UTF-8"), "application/json") };
            return result;
        }