ASP.NET MVC + Jquery 实现Ajax下拉框数据三级联动

这是第一使用Jquery实现城市三级数据联动的实例！之前本人没有使用过Jquery，在WebForm的开发过程中，很多时候用的是ASP.NET Ajax,ajaxPro +JavaScript,从未使用过JS框架，最近在学习ASP.NET MVC,在最新的发布版本中，已经集成了Jquery 1.3.1，自然，也要学一学！发现使用Jquery代码果然写得比原始JS优雅！只是语法和方法太多，现在还没弄熟，还需要时间来学习．．．．．这次是第一次使用Jquery写客户端脚本，如果大家发现更好的实现方法，请给我留言！谢谢！

注明：ASP.NET MVC 1.0 ,作者:0x001;

View :

<script type="text/javascript">

    $(document).ready(function() {

        GetByJquery();

        $("#ddlProvince").change(function() { GetCity() });

        $("#ddlCity").change(function() { GetDistrict() });

    });

    function GetByJquery() {

        $("#ddlProvince").empty(); //清空省份SELECT控件

        $.getJSON("/ajax/GetProvinceList", function(data) {

            $.each(data, function(i, item) {

                $("<option></option>")

                    .val(item["ProvinceID"])

                    .text(item["ProvinceName"])

                    .appendTo($("#ddlProvince"));

            });

            GetCity();

        });     

    }

    function GetCity() {

        $("#ddlCity").empty(); //清空城市SELECT控件

        var url ="/ajax/GetCityList/" + $("#ddlProvince").val();

        $.getJSON(url, function(data) {

            $.each(data, function(i, item) {

                $("<option></option>")

                    .val(item["CityID"])

                    .text(item["CityName"])

                    .appendTo($("#ddlCity"));

            });

            GetDistrict();

        });

    }

    function GetDistrict() {

        $("#ddlDistrict").empty(); //清空市区SELECT控件

        var url = "/ajax/GetDistrictList/" + $("#ddlCity").val();

        $.getJSON(url, function(data) {

            $.each(data, function(i, item) {

                $("<option></option>")

                    .val(item["DistrictID"])

                    .text(item["DistrictName"])

                    .appendTo($("#ddlDistrict"));

            });

        });

    }

</script>

<table><tr><td><select id="ddlProvince"/></td><td><select id="ddlCity"/></td><td><select id="ddlDistrict" /></td></tr></table>

Controller :

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.Mvc;

using System.Web.Mvc.Ajax;

namespace MvcBBS.Controllers

{

    public class AjaxController : Controller

    {

        //

        // GET: /Ajax/

        /// <summary>

        /// 获取所有［省份］数据

        /// </summary>

        public ActionResult GetProvinceList()

        {

            if (!Request.IsAjaxRequest())

            {

                return Content("请不要非法方法,这是不道德的行为！");

            }

            BLL.Province bll = new MvcBBS.BLL.Province();

            List<MvcBBS.Model.S_Province> modellist = bll.GetProvinceList();

            return Json(modellist);

        }

        /// <summary>

        /// 获取某［省份］的所有［城市］数据

        /// </summary>

        public ActionResult GetCityList(int id)

        {

            if (!Request.IsAjaxRequest())

            {

                return Content("请不要非法方法,这是不道德的行为！");

            }

            BLL.Province bll = new MvcBBS.BLL.Province();

            List<MvcBBS.Model.S_City> modellist = bll.GetCityList(id);

            return Json(modellist);

        }

        /// <summary>

        /// 获取某［城市］的所有［市区］数据

        /// </summary>

        public ActionResult GetDistrictList(int id)

        {

            if (!Request.IsAjaxRequest())

            {

                return Content("请不要非法方法,这是不道德的行为！");

            }

            BLL.Province bll = new MvcBBS.BLL.Province();

            List<MvcBBS.Model.S_District> modellist = bll.GetDistrict(id);

            return Json(modellist);

        }

    }

}

我比较喜欢使用三层＋工厂模式来读写数据，O/R Mapping不太适合我的要求！我们写的项目经常不是为了方便移植，而是选择明确的数据库，需要更高的性能，更强的业务逻辑！大家看到上面的代码，应该很熟悉，从数据库读数据到List<>中返回，并使有ASP.NET MVC内置的Json方法转换数据并Response．

DAL :    

// BLL,Model就不贴出来了！

using System;

using System.Data;

using System.Text;

using System.Data.SqlClient;

using System.Collections.Generic;

using DBUtility;//请先添加引用

namespace MvcBBS.DAL

{

    public class Province

    {

        public Province()

        {}

        /// <summary>

        /// 获取所有省份数据

        /// </summary>

        /// <returns></returns>

        public List<Model.S_Province> GetProvinceList()

        {

            StringBuilder strSql = new StringBuilder();

            strSql.Append("SELECT ProvinceID,ProvinceName ");

            strSql.Append(" FROM S_Province ");

            List<Model.S_Province> modelList = new List<MvcBBS.Model.S_Province>();

            SqlDataReader dr = DbHelperSQL.ExecuteReader(strSql.ToString());           

            while (dr.Read())

            {

                 Model.S_Province _model = new MvcBBS.Model.S_Province();

                 _model.ProvinceID = int.Parse(dr["ProvinceID"].ToString());

                 _model.ProvinceName = dr.GetString(1);

                modelList.Add(_model);

            }

            dr.Close();

            return modelList;

        }

        /// <summary>

        /// 获取某省份的所有城市数据

        /// </summary>

        /// <param name="ProvinceID"></param>

        /// <returns></returns>

        public List<Model.S_City> GetCityList(int ProvinceID)

        {

            StringBuilder strSql = new StringBuilder();

            strSql.Append("SELECT CityID,CityName,ZipCode");

            strSql.Append(" FROM S_City ");

            strSql.Append(" WHERE ProvinceID=");

            strSql.Append(ProvinceID.ToString());

            List<Model.S_City> modelList = new List<MvcBBS.Model.S_City>();

            SqlDataReader dr = DbHelperSQL.ExecuteReader(strSql.ToString());

            while (dr.Read())

            {

                Model.S_City _model = new MvcBBS.Model.S_City();

                _model.CityID = int.Parse(dr["CityID"].ToString());

                _model.CityName = dr.GetString(1);

                _model.ZipCode = dr.GetString(2);

                _model.ProvinceID = ProvinceID;

                modelList.Add(_model);

            }

            dr.Close();

            return modelList;

        }

        /// <summary>

        /// 获取某城市的所有市区

        /// </summary>

        /// <param name="CityID"></param>

        /// <returns></returns>

        public List<Model.S_District> GetDistrict(int CityID)

        {

            StringBuilder strSql = new StringBuilder();

            strSql.Append("SELECT DistrictID,DistrictName");

            strSql.Append(" FROM S_District ");

            strSql.Append(" WHERE CityID=");

            strSql.Append(CityID.ToString());

            List<Model.S_District> modelList = new List<MvcBBS.Model.S_District>();

            SqlDataReader dr = DbHelperSQL.ExecuteReader(strSql.ToString());

            while (dr.Read())

            {

                Model.S_District _model = new MvcBBS.Model.S_District();

                _model.DistrictID = int.Parse(dr["DistrictID"].ToString());

                _model.DistrictName = dr.GetString(1);

                _model.CityID = CityID;

                modelList.Add(_model);

            }

            dr.Close();

            return modelList;

        }

    }

}