MVC二级联动使用$.ajax方法获取后端返回的字符串

在"MVC二级联动使用$.getJSON方法"中使用$.getJSON()获取后端返回的JSon。
本篇使用jQuery的$.ajax()获取后端返回的字符串，实现二级联动。

 

□ View Models

namespace MvcApplication1.Models
{
    public class Province
    {
        public int ID { get; set; }
        public string Name { get; set; }
    }

    public class City
    {
        public int ID { get; set; }
        public int ProvinceID { get; set; }
        public string Name { get; set; }
        public string ZipCode { get; set; }
    }
}

 

□ 模拟一个服务层获取数据

using System.Collections.Generic;
using System.Linq;
using MvcApplication1.Models;

namespace MvcApplication1
{
    public static class Service
    {
        public static List<Province> GetProvices()
        {
            List<Province> result = new List<Province>();
            result.Add(new Province(){ID = 1,Name = "山东省"});
            result.Add(new Province(){ID = 2,Name = "江苏省"});
            return result;
        }

        public static List<City> GetCitiesByProvince(int provinceId)
        {
            List<City> result = new List<City>();
            result.Add(new City(){ID=1,Name = "济南市",ProvinceID = 1,ZipCode = "001"});
            result.Add(new City() { ID = 2, Name = "青岛市", ProvinceID = 1, ZipCode = "002"});
            result.Add(new City() { ID = 3, Name = "南京市", ProvinceID = 2, ZipCode = "003" });
            result.Add(new City() { ID = 4, Name = "苏州市", ProvinceID = 2, ZipCode = "004" });

            return result.Where(r => r.ProvinceID == provinceId).ToList();
        }
    }
}

□ HomeController

直接产生<option></option>传递给前台视图。

using System;
using System.Collections.Generic;
using System.Text;
using System.Web.Mvc;
using MvcApplication1.Models;

namespace MvcApplication1.Controllers
{
    public class HomeController : Controller
    {
        public ActionResult Index()
        {
            return View();
        }

        public ActionResult GetProvinces()
        {
            StringBuilder sb = new StringBuilder();
            var provinces = Service.GetProvices();
            foreach (Province p in provinces)
            {
                sb.AppendFormat("<option value="{0}">{1}</option>",
                    p.ID, p.Name);
            }
            return Content(sb.ToString());
        }

        [HttpPost]
        public ActionResult GetCities(string id)
        {
            StringBuilder sb = new StringBuilder();
            if (!string.IsNullOrEmpty(id))
            {
                var cities = Service.GetCitiesByProvince(int.Parse(id));
                foreach (City c in cities)
                {
                    sb.AppendFormat("<option value="{0}">{1}</option>",
                        c.ID,
                        string.Concat(c.ZipCode, " ", c.Name));
                }
            }
            return Content(sb.ToString());
        }
    }
}

□ Home/Index.cshtml视图

@{
    ViewBag.Title = "Index";
    Layout = "~/Views/Shared/_Layout.cshtml";
}

选择省：<select id="p"></select> <br/>
选择市：<select id="c"></select>

@section scripts
{
    <script type="text/javascript">
        $(function() {
            getProvince();

            $('#p').change(function() {
                changeCity();
            });
        });

        //加载省
        function getProvince() {
            $.ajax({
                url: '@Url.Action("GetProvinces","Home")',
                type: 'post',
                cache: false,
                async: false,
                dataType: 'html',
                success: function(data) {
                    if (data.length > 0) {
                        $('#p').append($('<option></option>').val('').text('请选择'));
                        $('#p').append(data);
                    }

                }
            });
        }

        //设置城市清空
        function emptyCity() {
            $('#c').empty();
            $('#c').append($('<option></option>').val('').text('请选择'));
        }

        //根据省加载城市
        function changeCity() {
            var selectedProvinceId = $.trim($('#p option:selected').val());
            if (selectedProvinceId.length == 0) {
                emptyCity();
            } else {
                $.ajax({
                    url: '@Url.Action("GetCities","Home")',
                    type: 'post',
                    data: { id: selectedProvinceId },
                    cache: false,
                    async: false,
                    success: function(data) {
                        if (data.length > 0) {
                            $('#c').append(data);
                        }
                    }
                });
            }
        }
    </script>
}

结果：

 

参考资料：
※ Kevin Tseng