级联菜单最有名的是省市级联，如果你还没有这样的数据库，请从这里下载。

1：MODEL

准备3个Model，如下：

public class Province    {        public int id { get; set; }        public string provinceID { get; set; }        public string province { get; set; }    }    public class Province    {        public int id { get; set; }        public string provinceID { get; set; }        public string province { get; set; }    }    public class Area    {        public int id { get; set; }        public string areaID { get; set; }        public string area { get; set; }        public string father { get; set; }    }

2：Controller部分的数据获取

如下：

public class CityController : Controller    {        string conn = "Data Source=.;Initial Catalog=ForestFire;User Id=sa;Password=sa;";        public ActionResult Index()        {            return View("");        }        public ActionResult GetProvince()        {            if (!Request.IsAjaxRequest())            {                return Content("请不要非法方法,这是不道德的行为！");            }            string sql = "select * from dbo.povince";            using (DataSet ds = SqlHelper.ExecuteDataset(conn, CommandType.Text, sql))            {                var provinces = DataTableHelper.DataTable2Objects
    
     (ds.Tables[0]);                return Json(provinces, JsonRequestBehavior.AllowGet);                //return Json(provinces);            }        }        public ActionResult GetCity(string id)        {            if (!Request.IsAjaxRequest())            {                return Content("请不要非法方法,这是不道德的行为！");            }            string sql = "select * from dbo.city where father=@fatherID";            SqlParameter p1 = new SqlParameter("@fatherID", id);            using (DataSet ds = SqlHelper.ExecuteDataset(conn, CommandType.Text, sql, p1))            {                var citys = DataTableHelper.DataTable2Objects
     
      (ds.Tables[0]);                return Json(citys, JsonRequestBehavior.AllowGet);                //return Json(provinces);            }        }        public ActionResult GetArea(string id)        {            if (!Request.IsAjaxRequest())            {                return Content("请不要非法方法,这是不道德的行为！");            }            string sql = "select * from dbo.area where father=@areaID";            SqlParameter p1 = new SqlParameter("@areaID", id);            using (DataSet ds = SqlHelper.ExecuteDataset(conn, CommandType.Text, sql, p1))            {                var areas = DataTableHelper.DataTable2Objects
      (ds.Tables[0]);                return Json(areas, JsonRequestBehavior.AllowGet);                //return Json(provinces);            }        }    }
     
    

3：前台

如下：

<%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage
    
     " %>
     
          Index.aspx
     
         
          
          
      
        xxx
    
      
     
    

最后的效果：

代码下载：