ASP.NET M5C实现城市或车型三级联动
作者：袖梨
2023-08-11
这篇文章介绍了ASP.NET MVC实现城市或车型三级联动的方法，文中通过示例代码介绍的非常详细。对大家的学习或工作具有一定的参考借鉴价值，需要的朋友可以参考下
三级或多级联动的场景经常会碰到，比如省、市、区，比如品牌、车系、车型，比如类别的多级联动......我们首先想到的是用三个select来展示，这是最通常的做法。但在另外一些场景中，比如确定搜索条件的时候，对于三级联动来说，可能选择1个，2个，或3个条件，我想，以下的方式可能更适合：
以上，可以只选择品牌，或同时选择品牌、车系，或同时选择品牌、车系、车型，最后把选择的内容展示到input上，并以逗号隔开。
可以实现的功能包括：
点击最上面的input弹出div，此时只显示品牌区域点击最左边拼音首字母，导航到对应的品牌上当把鼠标移动到某个品牌上，品牌为选中状态，其对应的车系显示在车系区域当鼠标不在任何品牌上，所有品牌都为不选中状态当把鼠标移动到某个车系上，车系为选中状态，其对应的车型显示在车型区域，选中车系的所属品牌也为选中状态当鼠标不在任何车系上，所有车系、品牌都为不选中状态当把鼠标移动到某个车型上，车型为选中状态，选中车型的所属车系为选中状态，选中车系所属品牌为选中状态当鼠标不在任何车型上，所有车型、车系、品牌为不选中状态点击品牌，品牌显示到input上点击车系，品牌、车系显示到input上，并以逗号隔开点击车型，品牌、车系、车型显示到input上，并以逗号隔开点击div上的关闭按钮或者页面空白区域，div隐藏界面的构成如下：
实现的思路大致这样：
给input点击事件，点击弹出品牌、车系、车型显示的div，并绑定页面空白区域的点击事件导航首字母指向锚点，品牌按首字母分类并提供锚点id在控制器中把品牌按照首字母分类，以json格式返回到前端，填充到tmpl模版，再追加到页面品牌区域给品牌添加鼠标移上事件，品牌为选中状态，对应的车系显示在车系区域给品牌添加鼠标移去事件给品牌添加点击事件，把点击品牌显示到input上给车系添加鼠标移上事件，当前车系为选中状态，其对应的车型显示在车型区域，其所属的品牌为选中状态给车系添加鼠标移去事件给车系添加点击事件，把点击车系和所属品牌显示到input上，以逗号隔开给车型添加鼠标移上事件，当前车型为选择状态，其所属父类车系为选中状态，车型所属父类品牌也为选中状态给车型添加点击事件，把点击车型和所属车系、品牌显示到input上，以逗号隔开给关闭按钮添加点击事件，关闭div，并解除页面空白区域点击事件的绑定领域先行，首先是有关品牌、车系、车型的模型：
public class CarCategory{public int Id { get; set; }public string Name { get; set; }public int PId { get; set; }public string FirstLetter { get; set; }public string AnchorName { get; set; }public int Level { get; set; }}PId属性用来表示父类Id,车系的父类Id为某个品牌Id,车型的父类Id为某个车系IdFirstLetter属性用来表示首字母，作为分组的条件AnchorName属性用来表示品牌的锚点id，车系和车型此项为空在ASP.NET MVC4中，在Shared/Layout.cshtml中，该有的css,js都必须有：
<head><meta charset="utf-8" /><meta name="viewport" content="width=device-width" /><title>@ViewBag.Title</title>@Styles.Render("~/Content/css")@RenderSection("styles", required: false)<link href="~/bootstrap/css/bootstrap.min.css" rel="stylesheet" />@Scripts.Render("~/bundles/jquery")<script src="~/bootstrap/js/bootstrap.min.js"></script></head><body>@RenderBody()@RenderSection("scripts", required: false)</body>模拟一个数据库，该数据库类可以获取到所有的品牌、车系、车型，以及根据品牌Id或车系Id获取对应的车系和车型。
public class Database{public static IEnumerable<CarCategory> GetCarCategories(){return new List<CarCategory>(){ new CarCategory(){Id = 0, Name = "奥迪",FirstLetter = "A",AnchorName = "aa", Level = 1, PId = -1}, new CarCategory(){Id = 1, Name = "奥斯顿·马丁",FirstLetter = "A",AnchorName = "aa", Level = 1, PId = -1}, new CarCategory(){Id = 2, Name = "宝骏",FirstLetter = "B",AnchorName = "bb", Level = 1, PId = -1}, new CarCategory(){Id = 3, Name = "巴博斯",FirstLetter = "B",AnchorName = "bb", Level = 1, PId = -1}, new CarCategory(){Id = 4, Name = "北汽威旺",FirstLetter = "B",AnchorName = "bb", Level = 1, PId = -1}, new CarCategory(){Id = 5, Name = "北汽制造",FirstLetter = "B",AnchorName = "bb", Level = 1, PId = -1}, new CarCategory(){Id = 6, Name = "奔驰",FirstLetter = "B",AnchorName = "bb", Level = 1, PId = -1}, new CarCategory(){Id = 7, Name = "别克",FirstLetter = "B",AnchorName = "bb", Level = 1, PId = -1}, new CarCategory(){Id = 8, Name = "宾利",FirstLetter = "B",AnchorName = "bb", Level = 1, PId = -1}, new CarCategory(){Id = 9, Name = "保时捷",FirstLetter = "B",AnchorName = "bb", Level = 1, PId = -1}, new CarCategory(){Id = 10, Name = "比亚迪",FirstLetter = "B",AnchorName = "bb", Level = 1, PId = -1}, new CarCategory(){Id = 11, Name = "奔腾",FirstLetter = "B",AnchorName = "bb", Level = 1, PId = -1}, new CarCategory(){Id = 12, Name = "标致",FirstLetter = "B",AnchorName = "bb", Level = 1, PId = -1}, new CarCategory(){Id = 13, Name = "本田",FirstLetter = "B",AnchorName = "bb", Level = 1, PId = -1}, new CarCategory(){Id = 14, Name = "宝马",FirstLetter = "B",AnchorName = "bb", Level = 1, PId = -1}, new CarCategory(){Id = 15, Name = "北京汽车",FirstLetter = "B",AnchorName = "bb", Level = 1, PId = -1}, new CarCategory(){Id = 16, Name = "昌河",FirstLetter = "C",AnchorName = "cc", Level = 1, PId = -1}, new CarCategory(){Id = 17, Name = "长安",FirstLetter = "C",AnchorName = "cc", Level = 1, PId = -1}, new CarCategory(){Id = 18, Name = "长城",FirstLetter = "C",AnchorName = "cc", Level = 1, PId = -1}, new CarCategory(){Id = 19, Name = "奥迪A4",FirstLetter = "A",AnchorName = "", Level = 2, PId = 0}, new CarCategory(){Id = 20, Name = "奥迪A6L",FirstLetter = "A",AnchorName = "", Level = 2, PId = 0}, new CarCategory(){Id = 21, Name = "奥迪Q3",FirstLetter = "A",AnchorName = "", Level = 2, PId = 0}, new CarCategory(){Id = 22, Name = "奥迪A4舒适版",FirstLetter = "A",AnchorName = "", Level = 3, PId = 19}, new CarCategory(){Id = 23, Name = "奥迪A4尊贵版",FirstLetter = "A",AnchorName = "", Level = 3, PId = 19}, new CarCategory(){Id = 24, Name = "奥迪A6L舒适版",FirstLetter = "A",AnchorName = "", Level = 3, PId = 20}, new CarCategory(){Id = 25, Name = "奥迪A6L黄金版",FirstLetter = "A",AnchorName = "", Level = 3, PId = 20}, new CarCategory(){Id = 26, Name = "奥迪Q3舒适版",FirstLetter = "A",AnchorName = "", Level = 3, PId = 21}, new CarCategory(){Id = 27, Name = "奥迪Q3至尊版",FirstLetter = "A",AnchorName = "", Level = 3, PId = 21},};}//根据品牌或车系I获取所有车系或车型public static IEnumerable<CarCategory> GetCarCategoriesByPId(int pid){return GetCarCategories().Where(c => c.PId == pid);}} 在HomeController中，在前端页面加载的时候，这里提供一个分组好的所有品牌的json格式给前端；当前端把鼠标移动到某个品牌上，这里根据品牌Id返回车系的json格式给前端；当前端把鼠标移动到某个车系上，这里根据车系Id返回车型的json格式给前端。
public class HomeController : Controller{public ActionResult Index(){return View();}//获取所有品牌public ActionResult GetPinPai(){var allPinPai = Database.GetCarCategories().Where(c => c.Level == 1).OrderBy(c => c.Id);var result = from p in allPinPaigroup p by new{p.FirstLetter,p.AnchorName}into gselect new {firstletter = g.Key.FirstLetter, anchor = g.Key.AnchorName, pinpais = g};return Json(result, JsonRequestBehavior.AllowGet);}//根据品牌Id获取车系[HttpPost]public ActionResult GetCheXiByPId(int pid) {var allCheXi = Database.GetCarCategoriesByPId(pid).OrderBy(c => c.Id);var result = from c in allCheXiselect new {chexi = c.Name, cxid = c.Id, parentId = c.PId};return Json(result);}//根据车系Id获取车型[HttpPost]public ActionResult GetCheXingByCxId(int cxid) {var allCheXing = Database.GetCarCategoriesByPId(cxid).OrderBy(c => c.Id);var result = from c in allCheXing select new { chexing = c.Name, chexingid = c.Id, parentId = c.PId };return Json(result);}} 在Home/Index.cshtml视图中，品牌、车系、车型内容都是先填充到tmpl模版中，然后追加到页面某个区域上的。
@{ViewBag.Title = "Index";Layout = "~/Views/Shared/_Layout.cshtml";}@section styles{<link href="~/Content/CarSelect.css" rel="external nofollow"rel="stylesheet" />}<div class="input-group"> <input type="text" id="mychoice" class="form-control"> <span class="input-group-btn"><button class="btn btn-default" type="button">∨</button> </span></div><div id="carcategory-picker-outer"><a href="javascript:void(0)" rel="external nofollow"class="cancel"></a><div id="carcategory-picker-inner"><div id="pinpai" class="carcategory-list"><h6>请选择品牌</h6><div id="PreLetter"><a href="#aa" rel="external nofollow" >A</a><a href="#bb" rel="external nofollow" >B</a><a href="#cc" rel="external nofollow" >C</a><a href="#dd" rel="external nofollow" >D</a><a href="#ff" rel="external nofollow" >F</a><a href="#gg" rel="external nofollow" >G</a><a href="#hh" rel="external nofollow" >H</a><a href="#jj" rel="external nofollow" >J</a><a href="#kk" rel="external nofollow" >K</a><a href="#ll" rel="external nofollow" >L</a><a href="#mm" rel="external nofollow" >M</a><a href="#nn" rel="external nofollow" >N</a><a href="#oo" rel="external nofollow" >O</a><a href="#qq" rel="external nofollow" >Q</a><a href="#rr" rel="external nofollow" >R</a><a href="#ss" rel="external nofollow" >S</a><a href="#ww" rel="external nofollow" >W</a><a href="#xx" rel="external nofollow" >X</a><a href="#yy" rel="external nofollow" >Y</a><a href="#zz" rel="external nofollow" >Z</a></div><div id="AllPinPai"></div></div><div id="chexi" class="carcategory-list"><h6>请选择车系</h6><div id="AllCheXi"> </div></div><div id="chexin" class="carcategory-list"><h6>请选择车型</h6><div id="AllCheXing"> </div></div></div></div>@section scripts{<script src="~/Scripts/jquery.tmpl.min.js"></script><script type="text/javascript">$(function() {//加载所有品牌$.getJSON('@Url.Action("GetPinPai", "Home")', function(data) {$('#pinpaiTemplate').tmpl(data).appendTo('#AllPinPai');});//点击input弹出品牌车系车型选择$('#mychoice').on("click", function() {$('#carcategory-picker-outer').css('display', 'block');$("body").bind("mousedown", onBodyDown);//绑定鼠标单击事件});//点击关闭按钮隐藏品牌车系车型选择$('.cancel').on("click", function() {hideMenu();});//给所有品牌加上鼠标移动上事件$('#AllPinPai').on("mouseover", ".ppm", function() {$(this).addClass('selected');$('#chexi').css("display", "block");$.post('@Url.Action("GetCheXiByPId","Home")', { 'pid': $(this).attr('pid') }, function (data) {$('#AllCheXi').empty();$('#AllCheXing').empty();$('#chexiTemplate').tmpl(data).appendTo('#AllCheXi');});});//给所有品牌加上鼠标移去事件$('#AllPinPai').on("mouseout", ".ppm", function () {$(this).removeClass('selected');});//品牌点击事件$('#AllPinPai').on("click", ".ppm", function () {$('#mychoice').val('');$('#mychoice').val($(this).text());hideMenu();});//给车系加上鼠标移动上事件$('#AllCheXi').on("mouseover", ".cxm", function () {//取取当前车系的父类Idvar parentId = $(this).attr('parentid');//把品牌中该父类添加selected这个类$('#AllPinPai').find("a[pid='" + parentId + "']").addClass('selected');$(this).addClass('selected');$('#chexin').css("display", "block");$.post('@Url.Action("GetCheXingByCxId","Home")', { 'cxid': $(this).attr('pid') }, function (data) {$('#AllCheXing').empty();$('#chexingTemplate').tmpl(data).appendTo('#AllCheXing');});});//给车系加上鼠标移去事件$('#AllCheXi').on("mouseout", ".cxm", function () {$(this).removeClass('selected');//取取当前车系的父类Idvar parentId = $(this).attr('parentid');//把品牌中该父类添加selected这个类$('#AllPinPai').find("a[pid='" + parentId + "']").removeClass('selected');});//车系点击事件$('#AllCheXi').on("click", ".cxm", function () {$('#mychoice').val('');//取取当前车系的父类Idvar parentId = $(this).attr('parentid');$('#mychoice').val($('#AllPinPai').find("a[pid='" + parentId + "']").text() + "," + $(this).text());hideMenu();});//给车型加上鼠标移上事件$('#AllCheXing').on("mouseover", ".cxim", function () {//取出车型的父类idvar parentId = $(this).attr('parentid');//把车系中该父类添加selected这个类$('#AllCheXi').find("a[pid='" + parentId + "']").addClass('selected');//取出车系的父类idvar parentparentId = $('#AllCheXi').find("a[pid='" + parentId + "']").attr('parentid');//把品牌中该父类添加selected这个类$('#AllPinPai').find("a[pid='" + parentparentId + "']").addClass('selected');});//给车型加上鼠标移去事件$('#AllCheXing').on("mouseout", ".cxim", function () {//取出车型的父类idvar parentId = $(this).attr('parentid');//把车系中该父类添加selected这个类$('#AllCheXi').find("a[pid='" + parentId + "']").removeClass('selected');//取出车系的父类idvar parentparentId = $('#AllCheXi').find("a[pid='" + parentId + "']").attr('parentid');//把品牌中该父类添加selected这个类$('#AllPinPai').find("a[pid='" + parentparentId + "']").removeClass('selected');});//车型点击事件$('#AllCheXing').on("click", ".cxim", function () {$('#mychoice').val('');//取出车型的父类idvar parentId = $(this).attr('parentid');//取出车系的父类idvar parentparentId = $('#AllCheXi').find("a[pid='" + parentId + "']").attr('parentid');$('#mychoice').val($('#AllPinPai').find("a[pid='" + parentparentId + "']").text() + "," + $('#AllCheXi').find("a[pid='" + parentId + "']").text() + "," + $(this).text());hideMenu();});});//隐藏树并解除绑定function hideMenu() {$("#carcategory-picker-outer").fadeOut("fast");$("body").unbind("mousedown", onBodyDown);}//鼠标单击空白处事件function onBodyDown(event) {if (!(event.target.id == "mychoice" || event.target.id == "carcategory-picker-outer" || $(event.target).parents("#carcategory-picker-outer").length > 0)) {hideMenu();}}</script><script id="pinpaiTemplate" type="text/x-jQuery-tmpl"><dl><dt id="${anchor}">${firstletter}</dt>{{if pinpais}}{{each pinpais}}<dd><a class="ppm" pid="${$value.Id}">${$value.Name}</a></dd>{{/each}}{{else}}<dd>没有此品牌</dd>{{/if}}</dl></script><script id="chexiTemplate" type="text/x-jQuery-tmpl"><dl><dd><a class="cxm" pid="${cxid}" parentid="${parentId}">${chexi}</a></dd></dl></script><script id="chexingTemplate" type="text/x-jQuery-tmpl"><dl><dd><a class="cxim" pid="${chexingid}" parentid="${parentId}">${chexing}</a></dd> </dl></script>}css部分如下，关闭按钮可自找。
#carcategory-picker-outer {background: #f9f9f9;padding: 10px;width: 640px;height: 380px;position: relative;display: none;}#PreLetter {border: 0px solid blue;width: 21px;float: left;}#PreLetter a:link{display: block;text-decoration: none;clear: both;font-size: 10px;text-align: center;padding-top: 0px;border: 1px solid #e3e3e3;width: 15px;height: 15px;background-color: #e9e9e9;margin-top: 2px;font-weight: bold;}#PreLetter a:hover {border: 1px solid blue;}#PreLetter a:visited {border: 1px solid #e3e3e3;}#pinpai {border: 0px solid green;float: left;}#AllPinPai {border: 1px solid #e3e3e3;margin-left: 5px;float: left;padding-bottom: 0px;width: 120px;height: 340px;overflow-y: auto;}#AllPinPai dl dd a {text-decoration: none;display: block;padding-left: 10px;}#AllPinPai dl dd {padding-left: 0px;}#AllPinPai dl dd a:hover {/*background-color: gray;*/color: white;}#AllPinPai dl {margin-bottom: 5px;}#chexi {border: 0px solid orange;float: left;margin-left: 10px;display: none;}#AllCheXi {width: 150px;height: 340px;overflow-y: auto;border: 1px solid #e3e3e3;}#AllCheXi dl dd a {text-decoration: none;display: block;padding-left: 10px;}#AllCheXi dl dd {padding-left: 0px;}#AllCheXi dl dd a:hover {color: white;}#AllCheXi dl {margin-bottom: 5px;}#chexin {border: 0px solid red;float: left;margin-left: 10px;display: none;}#AllCheXing {width: 300px;height: 340px;overflow-y: auto;border: 1px solid #e3e3e3;}#AllCheXing dl dd a {text-decoration: none;display: block;padding-left: 10px;}#AllCheXing dl dd {padding-left: 0px;}#AllCheXing dl dd a:hover {background-color: gray;color: white;}#AllCheXing dl {margin-bottom: 5px;}dt {background-color: #e9e9e9;padding-left: 10px;}dl {border: 0px solid red;}dd {padding-left: 10px;line-height: 15px;margin-top: 5px;margin-bottom: 0px;border: 0px solid blue;/*background-color: gray;*/}.selected {background-color: gray;color: white;}.cancel {width: 20px;height: 17px;position: absolute;display: block;top: 20px;right: 20px;background-image: url("../img/close.png");border: 1px solid orangered;background-color: orangered;}.input-group {width: 640px;} 
