using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Runtime.Serialization.Json;

using System.IO;

namespace JsonTest

{

    class JsonHelp

    {

        public JsonHelp()

    {

        //

        // TODO: Add constructor logic here

        //

    }

    /// <summary>

    /// 把对象序列化 JSON 字符串

    /// </summary>

    /// <typeparam name="T">对象类型</typeparam>

    /// <param name="obj">对象实体</param>

    /// <returns>JSON字符串</returns>

    public static string GetJson<T>(T obj)

    {

        //记住 添加引用 System.ServiceModel.Web

        /**

         * 如果不添加上面的引用,System.Runtime.Serialization.Json; Json是出不来的哦

         * */

        DataContractJsonSerializer json = new DataContractJsonSerializer(typeof(T));

        using (MemoryStream ms = new MemoryStream())

        {

            json.WriteObject(ms, obj);

            string szJson = Encoding.UTF8.GetString(ms.ToArray());

            return szJson;

        }

    }

    /// <summary>

    /// 把JSON字符串还原为对象

    /// </summary>

    /// <typeparam name="T">对象类型</typeparam>

    /// <param name="szJson">JSON字符串</param>

    /// <returns>对象实体</returns>

    public static T ParseFormJson<T>(string szJson)

    {

        T obj = Activator.CreateInstance<T>();

        using (MemoryStream ms = new MemoryStream (Encoding.UTF8.GetBytes(szJson)))

        {

            DataContractJsonSerializer dcj = new DataContractJsonSerializer(typeof(T));

            return (T)dcj.ReadObject(ms);

        }

    }

    }

}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace JsonTest

{

  public  class testData

    {

        public testData()

    {

    }

    public int Id { get; set; }

    public string Name { get; set; }

    public string Sex { get; set; }

    }

}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace JsonTest

{

    class Program

    {

        static void Main(string[] args)

        {

            //实体类转json

            testData t1 = new testData();

            t1.Id = 1;

            t1.Name = "001姓名";

            t1.Sex = "男";

            testData t2 = new testData();

            t2.Id = 2;

            t2.Name = "002姓名";

            t2.Sex = "男";

            testData t3 = new testData();

            t3.Id = 3;

            t3.Name = "003姓名";

            t3.Sex = "男";

            List<testData> tlist = new List<testData>();

            tlist.Add(t1);

            tlist.Add(t2);

            tlist.Add(t3);

         Console.WriteLine(JsonHelp.GetJson<List<testData>>(tlist));

        // Console.ReadKey();

           //json转实体类

         List<testData> tl = JsonHelp.ParseFormJson <List<testData>>(JsonHelp.GetJson<List<testData>>(tlist));

         Console.WriteLine(tl.Count);

         Console.WriteLine(tl[0].Name);

         Console.ReadKey();

        }

    }

}