[转]jquery getJSON 数据联动（采用序列化和反序列化获取数据） .

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <script src="Scripts/jquery-1.4.1.js" type="text/javascript"></script>
    <script type="text/javascript">
        $(document).ready(function () {

            GetByJquery("#area", 0);

            $("#area").change(function () {
                GetByJquery("#subarea", $("#area").val());
            });

            $("#btnGet").click(function () {
                alert($("#area").val() + "--" + $("#area option:selected").text());
            });
        });

SelectAjax.ashx文件：

/// <summary>
    /// SelectAjax 的摘要说明
    /// </summary>
    public class SelectAjax : IHttpHandler
    {

        public void ProcessRequest(HttpContext context)
        {
            context.Response.ContentType = "text/plain";

string action = context.Request.QueryString["action"];

            if (("area").Equals(action))
            {
                string id = context.Request.QueryString["id"];
                if (!string.IsNullOrEmpty(id))
                    context.Response.Write(GetArea(id));
                else context.Response.Write("");
            }
        }

        private string GetArea(string id)
        {
            List<Area> areaList = new List<Area>();

            if (id == "0")
            {
                areaList.Add(new Area
                {
                    AreaID = "01",
                    AreaName = "罗湖区",
                    PID = "0"
                });
                areaList.Add(new Area
                {
                    AreaID = "02",
                    AreaName = "福田区",
                    PID = "0"
                });
            }

            if (id == "01")
            {
                areaList.Add(new Area
                {
                    AreaID = "0101",
                    AreaName = "莲塘",
                    PID = "01"
                });
                areaList.Add(new Area
                {
                    AreaID = "0102",
                    AreaName = "黄贝岭",
                    PID = "01"
                });
            }
            if (id == "02")
            {
                areaList.Add(new Area
                {
                    AreaID = "0201",
                    AreaName = "八卦岭",
                    PID = "02"
                });
                areaList.Add(new Area
                {
                    AreaID = "0202",
                    AreaName = "华强",
                    PID = "02"
                });
            }

return Serialize(areaList);
}

        /// <summary>
        /// Json序列化
        /// </summary>
        /// <typeparam name="T">泛型</typeparam>
        /// <param name="t">泛型</param>
        /// <returns>序列化</returns>
        private string Serialize(object obj)
        {
            JavaScriptSerializer js = new JavaScriptSerializer();
            return js.Serialize(obj);
        }
        /// <summary>
        /// Json反序列化
        /// </summary>
        /// <typeparam name="T">泛型</typeparam>
        /// <param name="strJson">泛型</param>
        /// <returns>反序列化</returns>
        private T Deserialize<T>(string strJson)
        {
            JavaScriptSerializer js = new JavaScriptSerializer();
            return js.Deserialize<T>(strJson);
        }

        public class Area
        {
            public string AreaID { get; set; }
            public string AreaName { get; set; }
            public string PID { get; set; }
        }

        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
    }