C#对象转换为Json格式

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ServiceModel;
using System.ServiceModel.Web;
using System.IO;
using System.Runtime.Serialization.Json;
using System.Runtime.Serialization;


class Program
    {
        //write object 写 object 2 json
        public static string ToJson<T>(T t)
        {
            DataContractJsonSerializer ds = new DataContractJsonSerializer(typeof(T));
            MemoryStream ms = new MemoryStream();
            ds.WriteObject(ms, t);
 
            string strReturn = Encoding.UTF8.GetString(ms.ToArray());
            ms.Close();
            return strReturn;
        }
 
        //write object 写 object 2 json
        public static string ToJson2<T>(T t)
        { 
            DataContractJsonSerializer serializer = new DataContractJsonSerializer(typeof(T));
            MemoryStream stream = new MemoryStream();
            serializer.WriteObject(stream, t);
            String result = Encoding.UTF8.GetString(stream.ToArray());
            return result;
        }
 
        //read object 读取 json 2 object
        public static T FromJson<T>(string strJson) where T : class
        {
            DataContractJsonSerializer ds = new DataContractJsonSerializer(typeof(T));
            MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(strJson));
            return ds.ReadObject(ms) as T;
        }
 
        //execute
        static void Main(string[] args)
        {
            User u = new User(1, "EE", "123");
            Console.WriteLine(ToJson2<User>(u));
            Console.ReadLine();
        }