错误界面：

这个就是返回对象没有转换成json

就是要再返回的头部添加application/json

代码：

using System;using System.Collections.Generic;using System.Linq;using System.Net.Http;using System.Net.Http.Formatting;using System.Net.Http.Headers;using System.Web;namespace WorkOrderManage.API.Utility{    public class JsonContentNegotiator : IContentNegotiator    {        private readonly JsonMediaTypeFormatter _jsonFormatter;        public JsonContentNegotiator(JsonMediaTypeFormatter formatter)        {            _jsonFormatter = formatter;        }        public ContentNegotiationResult Negotiate(Type type, HttpRequestMessage request, IEnumerable
     
       formatters)        {            var result = new ContentNegotiationResult(_jsonFormatter, new MediaTypeHeaderValue("application/json"));            return result;        }        public static DateTime GetTime(string timeStamp)        {            DateTime dtStart = TimeZone.CurrentTimeZone.ToLocalTime(new DateTime(1970, 1, 1));            long lTime = long.Parse(timeStamp + "0000000");            TimeSpan toNow = new TimeSpan(lTime);            return dtStart.Add(toNow);        }    }}
     

再在全局文件Global.asax的Application_start里面添加

var jsonFormatter = new JsonMediaTypeFormatter();            GlobalConfiguration.Configuration.Services.Replace(typeof(IContentNegotiator), new JsonContentNegotiator(jsonFormatter));

返回界面

发现content-type里面有application/json

 

或者直接添加

GlobalConfiguration.Configuration.Formatters.JsonFormatter.MediaTypeMappings.Add(new QueryStringMapping("json", "true", "application/json"));