用AJAX做下拉框级联

 <script language="javascript"type="text/javascript"> 2                         $(document).ready(function () { 3                             var gettime = function () { 4                                 var dt = this.options[this.selectedIndex].value;//获取当前触发Change事件select控件当前选中项的值 5                                 $.get("./FTimeList", { date: dt, time: new Date().getTime() }, function (data) {//将选中值传入,作为查询条件 6                                     var time = data.getElementsByTagName("time");//以<time></time>为标签去子元素,list 7                                     var hl = ""; 8                                     for (var i = 0; i < time.length; i++) { 9                                         hl += "<option value=\"" + time[i].firstChild.data + "\" >" + time[i].firstChild.data + "</option>";10                                         //遍历time赋值给h1(此处做成<option>标签样式)11                                     }12                                     $("#DroTime").html(hl); //赋值给ID为DroTime的dropdownlist实现绑定13                                 });14                             }15                             $("#DroDate").change(gettime);//事件绑定是ID为DroDate的下拉框触发事件，然后将你选中的值传到后台，然后根据这个值查出数据返回绑定　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　给标签为DroTime的下拉框16                             var getdate = function () { //和上面差不多，是下一级的级联选项，如果不需要可以不用17                                 dc = this.options[this.selectedIndex].value;18                                 $.get("./STeaTime", { TID: dc, time: new Date().getTime() }, function (data) {19                                     var date = data.getElementsByTagName("date");20                                     var hl = "";21                                     for (var i = 0; i < date.length; i++) {22                                         hl += "<option>" + date[i].firstChild.data + "</option>";23                                     }24                                     $("#DroDate").html(hl);25                                     gettime;26                                 });27                             }28                             $("#DroTec").change(getdate);29                         });30                     </script> 
　　　　　　以下是后台Action代码:

 1         public ActionResult FTimeList(string date) 2         { 3             string strr="<?xml version=\"1.0\"?><node>";//加XML文件头 4             if (TeacherID != null) 5             { 6                 var TeacherName = from s4 in wtDB.View_TeacherName 7                                   where s4.TeacherID == TeacherID 8                                   select s4; 9                 if (TeacherName.Count() > 0)10                 {11                    12                     var TeacherTime = from s4 in wtDB.WT_AvailableTime13                                       where s4.CustomerId == TeacherName.First().Id && s4.Date ==Convert.ToDateTime(date)//用户ID14                                       select new { s4.StartTimeId, s4.Date };15                     List<SelectListItem> TimeList = new List<SelectListItem>();// 老师有空时间16                     List<SelectListItem> DateList = new List<SelectListItem>();//日期17                     if (TeacherTime.Count() > 0)18                     {19                         foreach (var time in TeacherTime)20                         {21                             var timeinfo = from s5 in wtDB.WT_Hours22                                            where s5.Id == time.StartTimeId23                                            select s5;//前面的都可以忽略，我功能上要用到的查询语句24                             foreach (var time2 in timeinfo)25                             {26                                 strr += "<time>" + time2.Time + "</time>";//构造返回的数据，以<time>为节点，前台也以<time>为节点取值27                             }28                         29 30                         }31                     }32                 }33             }34             strr += "</node>";//结尾35            36             return Content(strr, "text/xml");37         }