using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Runtime.Serialization.Json;
using System.ServiceModel.Web;///記得引用這個命名空間
using System.IO;
using System.Text;
/// summary>
/// Summary description for JsonHelper
/// /summary>
public class JsonHelper
{
    public JsonHelper()
    {
        //
        // TODO: Add constructor logic here
        //
    }
    /// summary>
    /// 把對象序列化 JSON 字符串
    /// /summary>
    /// typeparam name="T">對象類型/typeparam>
    /// param name="obj">對象實體/param>
    /// returns>JSON字符串/returns>
    public static string GetJsonT>(T obj)
    {
        //記住 添加引用 System.ServiceModel.Web
        /**
         * 如果不添加上面的引用,System.Runtime.Serialization.Json; Json是出不來的哦
         * */
        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字符串還原為對象
    /// /summary>
    /// typeparam name="T">對象類型/typeparam>
    /// param name="szJson">JSON字符串/param>
    /// returns>對象實體/returns>
    public static T ParseFormJsonT>(string szJson)
    {
        T obj = Activator.CreateInstanceT>();
        using (MemoryStream ms = new MemoryStream (Encoding.UTF8.GetBytes(szJson)))
        {
            DataContractJsonSerializer dcj = new DataContractJsonSerializer(typeof(T));
            return (T)dcj.ReadObject(ms);
        }
    }
}

public class TestData
{
    public TestData()
    {
    }
    public int Id { get; set; }
    public string Name { get; set; }
    public string Sex { get; set; }
}

%@ Page Language="C#" %>
!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

script runat="server">
    protected void Page_Load(object sender, EventArgs e)
    {
        string jsonStr = string.Empty;
        ListTestData> tds = new ListTestData>();
        //測試數據
        for (int i = 1; i 4; i++)
        {
            tds.Add(new TestData() { Id = i, Name = "jinho" + i, Sex = "male" });
        }        //把一個list轉換為json字符串
        jsonStr = JsonHelper.GetJsonListTestData>>(tds);
        Response.Write(jsonStr);
        this.Page.ClientScript.RegisterStartupScript(this.GetType(), "json", "getJson(" + jsonStr + ");", true);
    }

/script>
script type="text/javascript">
    function getJson(jsonStr) {        //使用eval函數
        var json = eval(jsonStr);         //因為上面為list集合
        for (var i = 0; i json.length; i++) {
            alert(json[i].Id + "Name:" + json[i].Name);
        }
    }
/script>
html xmlns="http://www.w3.org/1999/xhtml">
head runat="server">
    title>/title>
/head>
body>
    form id="form1" runat="server">
    div>

    /div>
    /form>
/body>
/html>