public class DP_Provice
{
public int proviceID { get; set; }
public string ProviceName { get; set; }
public int ProviceNode { get; set; }
public virtual List<DP_City> citySource { get; set; }
}

public class DP_City
{
public int CityNode { get; set; }
public string CityName { get; set; }
public string ProviceNode { get; set; }
}

public static class DPDataSource
{
public static List<DP_Provice> InitalData()
{
List<DP_Provice> source = new List<DP_Provice>
{
new DP_Provice{ ProviceNode=1, ProviceName="北京", citySource=new List<DP_City>{
new DP_City{
CityNode=11, CityName="北京海淀"
},
new DP_City{
CityNode=12,CityName="北京西城"
}
}},
new DP_Provice{ ProviceNode=2, ProviceName="山東", citySource=new List<DP_City>{
new DP_City{
CityNode=21, CityName="濟南"
},
new DP_City{
CityNode=22,CityName="德州"
}
}},
new DP_Provice{ ProviceNode=3, ProviceName="河北", citySource=new List<DP_City>{
new DP_City{
CityNode=31, CityName="石家莊"
},
new DP_City{
CityNode=32,CityName="衡水"
}
}}
};

return source;
}
}

public ActionResult Index()
{
return View("DPShow");
}
List<DP_Provice> source = DPDataSource.InitalData();

public JsonResult GetProvinceSource()
{
if (source == null || source.Count < 0)
{
source = DPDataSource.InitalData();
}
return Json(source, JsonRequestBehavior.AllowGet);
}
public JsonResult GetCitySource(string proviceName)
{
source = DPDataSource.InitalData();
List<DP_City> citySource = new List<DP_City>();
citySource = source.Where(a => a.ProviceNode.ToString().Contains(proviceName)).First().citySource;
return Json(citySource, JsonRequestBehavior.AllowGet);
}

@model MvcApplication.Models.DP_Provice
@{
ViewBag.Title = "DPShow";
Layout = "~/Views/Shared/_Layout.cshtml";
}
<script type="text/javascript">
$(function myfunction() {
GetPlant();
//初始化省份數據
$("#ddlProvince").change(function ff() { //設置當省份下拉列表發生變化時，更新城市數據列表
GetCity();
});
});

function GetPlant() {
$("#ddlProvince").empty();
var url = "/Dropdown/GetProvinceSource/";
$.getJSON(url, function (data) {
$.each(data, function (i, item) {
$("<option></option>")
.val(item["ProviceNode"])
.text(item["ProviceName"])
.appendTo($("#ddlProvince"));
});
GetCity();
});
}
function GetCity() {
$("#ddlCity").empty();
var temp=$("#ddlProvince").val();
var url ="@Url.Action("GetCitySource", "Dropdown")" ;
//使用MVC3中Url.Action 方法參數依次為：aciton ; controller ; area ;

$.getJSON(url,{"proviceName":temp}, function (data) {
//中間需要用到參數 所以采用在getJSON方法中實現
$.each(data, function (i, item) {
$("<option></option>")
.val(item["CityNode"])
.text(item["CityName"])
.appendTo($("#ddlCity"));
});
});
}
</script>
<! DOCTYPE html />
<h2>
下拉列表聯動</h2>
<table>
<tr>
<td>
<select id="ddlProvince" />
</td>
<td>
<select id="ddlCity" />
</td>
</tr>
</table>