在需要处理很多分类以及导航的时候，树形导航菜单就比较适合。例如在汽车之家上：
页面主要分两部分，左边是导航菜单，右边显示对应的内容。现在，我们就在ASP.NET MVC 4 下临摹一个，如下：
实现的效果包括：
1、点击导航菜单上的品牌，左侧显示该品牌下的所有车型。
2、点击导航菜单上的车系，左侧显示该车系下的所有车型。
3、点击左侧上方的字母导航，锚点跳到导航菜单的对应部分。
4、页面加载完毕，显示所有品牌和车系，即树形导航完全展开。
5、点击导航菜单上的品牌，收缩或展开对应的车系，收缩时，品牌前面图标为+号，展开时，品牌前面的图片为-号。
......
源码部分，在这里。
思路呢？
页面分成左右2部分，使用Bootstrap轻松实现：
<div class="row">
<div class="col-md-2 col-lg-2 col-sm-2">
</div>
<div class="col-md-10 col-lg-10 col-sm-10">
</div>
</div>
左侧最上方的字母导航，被放在一个div中，页面加载的时候向控制器动态请求。
品牌上方的字母归类，比如奥迪上方的字母A，实际上是一个div。
品牌和车系放在了ul中，比如奥迪品牌以及奥迪下的奥迪A4和奥迪A6车系。车系被放在了dl中。
树形菜单采用模版比较合适，先把数据填充到模版，再把模版追加到页面元素。
当点击左侧树形导航上的品牌或车系，右侧通过iframe来呈现对应的内容。
领域先行。有关品牌和车系就抽象成如下的类：
public class CarCategory
{
public int Id { get; set; }
public int ParentId { get; set; }
public string Name { get; set; }
public string FirstLetter { get; set; }
public string AnchorName { get; set; }
public int Level { get; set; }
public short DelFlag { get; set; }
}
有关车型就抽象成如下的类：
public class Car
{
public int Id { get; set; }
public int PinPaiId { get; set; }
public int CheXiId { get; set; }
public string Name { get; set; }
}
页面左侧呈现树形导航需要向控制器请求json数据，大致格式是：
首字母
锚点名称
所有品牌
品牌编号
品牌名称
所有车系
车系编号
车系名称
车系下车型的总数量
貌似有3层，那就从最里面这层开始建模。有关车系在树形导航中的显示：
public class CheXiForDisplay
{
public int CheXiId { get; set; }
public int TotalCount { get; set; }
public string CheXiName { get; set; }
}
有关品牌在树形导航中的显示：
public class PinPaiForDisplay
{
public int PinPaiId { get; set; }
public string PinPaiName { get; set; }
public List<CheXiForDisplay> CheXis { get; set; }
}
有关品牌车系分组的：
public class PinPaiCheXiForDisplay
{
public string FirstLetter { get; set; }
public string Anchor { get; set; }
public List<PinPaiForDisplay> PinPais { get; set; }
}
数据源从哪里来？模拟了一个：
public class Database
{
public static IEnumerable<CarCategory> GetAllCarCategories()
{
return new List<CarCategory>
{
new CarCategory(){Id = 1, ParentId = 0, Name = "奥迪",FirstLetter = "A", AnchorName = "AA", Level = 1, DelFlag = 0},
new CarCategory(){Id = 2, ParentId = 0, Name = "宝马",FirstLetter = "B", AnchorName = "BB", Level = 1, DelFlag = 0},
new CarCategory(){Id = 3, ParentId = 0, Name = "保时捷",FirstLetter = "B", AnchorName = "BB", Level = 1, DelFlag = 0},
new CarCategory(){Id = 4, ParentId = 0, Name = "长安",FirstLetter = "C", AnchorName = "CC", Level = 1, DelFlag = 0},
new CarCategory(){Id = 5, ParentId = 0, Name = "大众",FirstLetter = "D", AnchorName = "DD", Level = 1, DelFlag = 0},
new CarCategory(){Id = 6, ParentId = 0, Name = "东风",FirstLetter = "D", AnchorName = "DD", Level = 1, DelFlag = 0},
new CarCategory(){Id = 7, ParentId = 0, Name = "丰田",FirstLetter = "F", AnchorName = "FF", Level = 1, DelFlag = 0},
new CarCategory(){Id = 8, ParentId = 0, Name = "福特",FirstLetter = "F", AnchorName = "FF", Level = 1, DelFlag = 0},
new CarCategory(){Id = 9, ParentId = 1, Name = "奥迪A4",FirstLetter = "A", AnchorName = "AA", Level = 2, DelFlag = 0},
new CarCategory(){Id = 10, ParentId = 1, Name = "奥迪A6",FirstLetter = "A", AnchorName = "AA", Level = 2, DelFlag = 0},
new CarCategory(){Id = 11, ParentId = 2, Name = "宝马1",FirstLetter = "B", AnchorName = "BB", Level = 2, DelFlag = 0},
new CarCategory(){Id = 12, ParentId = 2, Name = "宝马2",FirstLetter = "B", AnchorName = "BB", Level = 2, DelFlag = 0},
new CarCategory(){Id = 13, ParentId = 3, Name = "保时捷1",FirstLetter = "B", AnchorName = "BB", Level = 2, DelFlag = 0},
new CarCategory(){Id = 14, ParentId = 3, Name = "保时捷2",FirstLetter = "B", AnchorName = "BB", Level = 2, DelFlag = 0},
new CarCategory(){Id = 15, ParentId = 4, Name = "长安1",FirstLetter = "C", AnchorName = "CC", Level = 2, DelFlag = 0},
new CarCategory(){Id = 16, ParentId = 4, Name = "长安2",FirstLetter = "C", AnchorName = "CC", Level = 2, DelFlag = 0},
new CarCategory(){Id = 17, ParentId = 5, Name = "大众1",FirstLetter = "D", AnchorName = "DD", Level = 2, DelFlag = 0},
new CarCategory(){Id = 18, ParentId = 5, Name = "大众2",FirstLetter = "D", AnchorName = "DD", Level = 2, DelFlag = 1},
new CarCategory(){Id = 19, ParentId = 6, Name = "东风1",FirstLetter = "D", AnchorName = "DD", Level = 2, DelFlag = 0},
new CarCategory(){Id = 20, ParentId = 6, Name = "东风2",FirstLetter = "D", AnchorName = "DD", Level = 2, DelFlag = 0},
new CarCategory(){Id = 21, ParentId = 7, Name = "丰田1",FirstLetter = "F", AnchorName = "FF", Level = 2, DelFlag = 0},
new CarCategory(){Id = 22, ParentId = 7, Name = "丰田2",FirstLetter = "F", AnchorName = "FF", Level = 2, DelFlag = 0},
new CarCategory(){Id = 23, ParentId = 8, Name = "福特1",FirstLetter = "F", AnchorName = "AFF", Level = 2, DelFlag = 0},
new CarCategory(){Id = 24, ParentId = 8, Name = "福特2",FirstLetter = "F", AnchorName = "AFF", Level = 2, DelFlag = 0}
};
}
public static IEnumerable<Car> GetAllCars()
{
return new List<Car>
{
new Car(){Id = 1, PinPaiId = 1, CheXiId = 9, Name = "奥迪A401"},
new Car(){Id = 2, PinPaiId = 1, CheXiId = 9, Name = "奥迪A402"},
new Car(){Id = 3, PinPaiId = 1, CheXiId = 10, Name = "奥迪A601"},
new Car(){Id = 4, PinPaiId = 1, CheXiId = 10, Name = "奥迪A602"},
new Car(){Id = 5, PinPaiId = 2, CheXiId = 11, Name = "宝马101"},
new Car(){Id = 6, PinPaiId = 2, CheXiId = 11, Name = "宝马102"},
new Car(){Id = 7, PinPaiId = 2, CheXiId = 12, Name = "宝马201"},
new Car(){Id = 8, PinPaiId = 2, CheXiId = 12, Name = "宝马202"},
new Car(){Id = 9, PinPaiId = 3, CheXiId = 13, Name = "保时捷101"},
new Car(){Id = 10, PinPaiId = 3, CheXiId = 13, Name = "保时捷102"},
new Car(){Id = 11, PinPaiId = 3, CheXiId = 14, Name = "保时捷201"},
new Car(){Id = 12, PinPaiId = 3, CheXiId = 14, Name = "保时捷202"},
new Car(){Id = 13, PinPaiId = 4, CheXiId = 15, Name = "长安101"},
new Car(){Id = 14, PinPaiId = 4, CheXiId = 15, Name = "长安102"},
new Car(){Id = 15, PinPaiId = 4, CheXiId = 16, Name = "长安201"},
new Car(){Id = 16, PinPaiId = 4, CheXiId = 16, Name = "长安202"},
new Car(){Id = 17, PinPaiId = 5, CheXiId = 17, Name = "大众101"},
new Car(){Id = 18, PinPaiId = 5, CheXiId = 17, Name = "大众102"},
new Car(){Id = 19, PinPaiId = 5, CheXiId = 18, Name = "大众201"},
new Car(){Id = 20, PinPaiId = 5, CheXiId = 18, Name = "大众202"},
new Car(){Id = 21, PinPaiId = 6, CheXiId = 19, Name = "东风101"},
new Car(){Id = 22, PinPaiId = 6, CheXiId = 19, Name = "东风102"},
new Car(){Id = 23, PinPaiId = 6, CheXiId = 20, Name = "东风201"},
new Car(){Id = 24, PinPaiId = 6, CheXiId = 20, Name = "东风202"},
new Car(){Id = 25, PinPaiId = 7, CheXiId = 21, Name = "丰田101"},
new Car(){Id = 26, PinPaiId = 7, CheXiId = 21, Name = "丰田102"},
new Car(){Id = 27, PinPaiId = 7, CheXiId = 22, Name = "丰田201"},
new Car(){Id = 28, PinPaiId = 7, CheXiId = 22, Name = "丰田202"},
new Car(){Id = 29, PinPaiId = 8, CheXiId = 23, Name = "福特101"},
new Car(){Id = 30, PinPaiId = 8, CheXiId = 23, Name = "福特102"},
new Car(){Id = 31, PinPaiId = 8, CheXiId = 24, Name = "福特201"},
new Car(){Id = 32, PinPaiId = 8, CheXiId = 24, Name = "福特202"}
};
}
}
好，现在可以向控制器要数据了。
public class HomeController : Controller
{
public ActionResult Index()
{
return View();
}
//获取所有首字母以及锚点的json
public ActionResult GetFirstLettersJson()
{
var allCarCategories = Database.GetAllCarCategories();
var result = from l in allCarCategories
group l by l.FirstLetter
into g
select new {firstletter = g.Key, anchor=g.ToList()[0].AnchorName};
return Json(result, JsonRequestBehavior.AllowGet);
}
//获取按首字母分组后的品牌车系json
public ActionResult GetPinPaiCheXiJson()
{
var allPinPais = Database.GetAllCarCategories().Where(c => c.Level == 1).OrderBy(c => c.FirstLetter);
var allPinPaisGroup = from p in allPinPais
group p by new
{
p.FirstLetter,
p.AnchorName
};
List<PinPaiCheXiForDisplay> result1 = new List<PinPaiCheXiForDisplay>();
foreach (var item in allPinPaisGroup)
{
//品牌车系
PinPaiCheXiForDisplay pinPaiCheXiForDisplay = new PinPaiCheXiForDisplay();
pinPaiCheXiForDisplay.FirstLetter = item.Key.FirstLetter;
pinPaiCheXiForDisplay.Anchor = item.Key.AnchorName;
//品牌
List<PinPaiForDisplay> pinPaiForDisplays = new List<PinPaiForDisplay>();
foreach (var pinpai in item.ToList())
{
PinPaiForDisplay pinPaiForDisplay = new PinPaiForDisplay();
pinPaiForDisplay.PinPaiId = pinpai.Id;
pinPaiForDisplay.PinPaiName = pinpai.Name;
//车系
List<CheXiForDisplay> cheXiForDisplays = new List<CheXiForDisplay>();
var cheXis = Database.GetAllCarCategories().Where(c => c.ParentId == pinpai.Id).OrderBy(c => c.Id);
foreach (var chexi in cheXis)
{
CheXiForDisplay cheXiForDisplay = new CheXiForDisplay();
cheXiForDisplay.CheXiId = chexi.Id;
cheXiForDisplay.CheXiName = chexi.Name;
cheXiForDisplay.TotalCount = cheXis.Count();
cheXiForDisplays.Add(cheXiForDisplay);
}
pinPaiForDisplay.CheXis = cheXiForDisplays;
pinPaiForDisplays.Add(pinPaiForDisplay);
}
pinPaiCheXiForDisplay.PinPais = pinPaiForDisplays;
result1.Add(pinPaiCheXiForDisplay);
}
return Json(result1, JsonRequestBehavior.AllowGet);
}
//根据品牌Id显示车型
public ActionResult GetCheXingsByPId(int pid)
{
var cars = Database.GetAllCars().Where(c => c.PinPaiId == pid);
return View(cars);
}
//根据车系Id显示车型
public ActionResult GetCheXingsByChexiId(int cxid)
{
var cars = Database.GetAllCars().Where(c => c.CheXiId == cxid);
return View(cars);
}
}
在Shared/_Layout.cshtml中，该引用的css,js都要引用上。
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width" />
<title>@ViewBag.Title</title>
<link href="~/bootstrap/css/bootstrap.min.css" rel="stylesheet" />
@Styles.Render("~/Content/css")
@RenderSection("styles", required: false)
@Scripts.Render("~/bundles/jquery")
<script src="~/bootstrap/js/bootstrap.min.js"></script>
</head>
<body>
@RenderBody()
@RenderSection("scripts", required: false)
</body>
Home/Index.cshtml就负责显示就行了。
@{
ViewBag.Title = "Index";
Layout = "~/Views/Shared/_Layout.cshtml";
}
@section styles
{
<link href="~/Content/sidemenu.css" rel="stylesheet" />
}
<div class="row">
<div class="col-md-2 col-lg-2 col-sm-2">
<!--字母导航开始-->
<div id="lDaoHang">
</div>
<!--字母导航结束-->
<!--树开始-->
<div id="cTreeDiv" style="overflow-x: hidden; overflow-y: scroll; height: 550px; width: 99%;">
</div>
<!--树结束-->
<div>
<dl id="test"></dl>
</div>
</div>
<div class="col-md-10 col-lg-10 col-sm-10">
<div class="carContent" id="carContent">
<iframe id="frameCar" src="" scrolling="no" frameborder="0" height="100%" width="100%" onload="this.height=this.contentWindow.document.documentElement.scrollHeight"></iframe>
</div>
</div>
</div>
@section scripts
{
<script src="~/Scripts/jquery.tmpl.min.js"></script>
<script type="text/javascript">
$(function () {
//加载首字母
$.getJSON('@Url.Action("GetFirstLettersJson", "Home")', function (data) {
$('#firstLetterTemplate').tmpl(data).appendTo('#lDaoHang');
});
//加载所有品牌车系
$.getJSON('@Url.Action("GetPinPaiCheXiJson", "Home")', function (data) {
$('#pinpaiTemplate').tmpl(data).appendTo('#cTreeDiv');
$('.pLink').each(function () {
pinPaiInitialState($(this));
});
});
//隐藏ifame所在div
$("#carContent").css("display", "none");
//点击品牌
$('#cTreeDiv').on("click", ".pLink", function () {
//切换
togglePinPaiState($(this));
//显示右边区域
var url = "/Home/GetCheXingsByPId?pid=" + $(this).attr('id');
$("#frameCar").attr("src", url);
$("#carContent").css("display", "block");
});
//点击车系
$('#cTreeDiv').on("click", ".cxLink", function () {
//显示右边区域
var url = "/Home/GetCheXingsByChexiId?cxid=" + $(this).attr('id');
$("#frameCar").attr("src", url);
$("#carContent").css("display", "block");
});
});
//品牌的初始状态,即把车系隐藏和品牌前面的图标为+号
var pstate = 0;
//品牌只有2种状态：所有车系隐藏，品牌前面的图标变为为+号；要么显示品牌下的所有车系，品牌前面的图标变为-号
//把车系隐藏和品牌前面的图标为+号，记为状态0
//把车系隐藏和品牌前面的图标为-号，记为状态1
function togglePinPaiState($pinpai) {
if (pstate == 0) {
var $i = $pinpai.parent().find("i");
var attr = $i.attr('class');
if (typeof attr !== typeof undefined && attr !== false) {
$i.removeClass("iconHide");
}
$i.addClass("iconShow");
$pinpai.parent().parent().find("dl").show();
pstate = 1;
} else {
var $j = $pinpai.parent().find("i");
var attr1 = $j.attr('class');
if (typeof attr1 !== typeof undefined && attr1 !== false) {
$j.removeClass("iconShow");
}
$j.addClass("iconHide");
$pinpai.parent().parent().find("dl").hide();
pstate = 0;
}
}
function pinPaiInitialState($pinpai) {
pstate = 0;
togglePinPaiState($pinpai);
}
</script>
<!--首字母模版-->
<script id="firstLetterTemplate" type="text/x-jQuery-tmpl">
<div class="lWrapper">
<a href="#${anchor}" class="lLink">${firstletter}</a>
</div>
</script>
<!--品牌模版-->
<script id="pinpaiTemplate" type="text/x-jQuery-tmpl">
<div class="lHeader" id="${Anchor}">${FirstLetter}</div>
<ul class="uTree">
{{if PinPais}}
{{each PinPais}}
<li>
<h5 class="font-bold">
<a href="javascript:void(0)" class="pLink" id="${$value.PinPaiId}"><i></i>${$value.PinPaiName}</a>
</h5>
<dl>
{{tmpl(CheXis) "#chexiTemplate"}}
</dl>
</li>
{{/each}}
{{else}}
<li>没有对应品牌</li>
{{/if}}
</ul>
</script>
<!--车系模版-->
<script id="chexiTemplate" type="text/x-jQuery-tmpl">
<dd><a id="${CheXiId}" href="javascript:void(0)" class="cxLink">${CheXiName}<em>(${TotalCount})</em></a></dd>
</script>
}
以上，
○ 从控制器返回的有关树形菜单的json数据，先填充到jquery.tmpl.min.js模版中，然后追加到页面上。
○ 树形菜单的展开或收缩，通过全局变量pstate在0和1之间的切换来实现，页面初次加载给变量pstate一个初始值。
另外，点击树形导航上的品牌，iframe加载的视图是Home/GetCheXingsByPId.cshtml
@model IEnumerable<MvcApplication1.Models.Car>
@{
ViewBag.Title = "GetCheXingsByPId";
Layout = "~/Views/Shared/_Layout.cshtml";
}
<h2>GetCheXingsByPId</h2>
<div>
@foreach (var item in Model)
{
<p>@item.Name </p>
}
</div>
点击树形导航上的车系，iframe加载的视图是Home/GetCheXingsByChexiId.cshtml
@model IEnumerable<MvcApplication1.Models.Car>
@{
ViewBag.Title = "GetCheXingsByChexiId";
Layout = "~/Views/Shared/_Layout.cshtml";
}
<h2>GetCheXingsByChexiId</h2>
<div>
@foreach (var item in Model)
{
<p>@item.Name </p>
}
</div
就这样。
