“ObjectContent`1”类型未能序列化内容类型“application/xml; charset=utf-8”的响应正文。

 public static void Register(HttpConfiguration config)
        {
            // Web API 配置和服务
            GlobalConfiguration.Configuration.Formatters.XmlFormatter.SupportedMediaTypes.Clear();
            // Web API 路由
            config.MapHttpAttributeRoutes();

            config.Routes.MapHttpRoute(
                name: "DefaultApi",
                routeTemplate: "api/{controller}/{id}",
                defaults: new { id = RouteParameter.Optional }
            );
        }