public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        string json = "{\"result\":\"0\",\"res_info\":\"ok\",\"queryorder_info\":\"info\"}";
        JavaScriptSerializer js = new JavaScriptSerializer();   //实例化一个能够序列化数据的类
        JsonClass list = js.Deserialize<JsonClass>(json);    //将json数据转化为对象类型并赋值给list
        string result = list.res_info;
        Response.Write(result);           
    }
    public struct JsonClass
    {
        public string result { get; set; }  //属性的名字,必须与json格式字符串中的"key"值一样。
        public string res_info { get; set; }
        public string queryorder_info { get; set; }
    }
}
原文:http://www.cnblogs.com/hanmian4511/p/4646060.html