将介绍如何用AngularJS构建一个强大的web前端系统。angularjs是由Google团队开发的一款非常优秀web前端框架。在当前如此多的web框架下，AngularJS能脱颖而出，从架构设计上就高人一等，双向数据绑定，依赖注入，指令，MVC，模板。Angular.js创新地把后台技术融入前端开发，扫去jQuery一度的光芒。用angularjs就像写后台代码，更规范，更结构化，更可控。
本文将介绍如何实现多限级导航菜单。
目录
1.静态多级菜单实现
2.动态多级菜单实现
1. 静态多级菜单实现
要实现多级菜单，我们要分两步走，第一步就是把静态菜单的功能实现，通过纯静态的HTML代码完成。第二步，通过Angluarjs进行动态实现，最后把数据和程序分离，通过Ajax加载多级菜单数据。
我们先从静态多级菜单开始动手，一个六级导航菜单是什么样子呢？
如上图所示，我们定义一些功能需求。
1级菜单是导航条上的文字。
当1级菜单导航事件被触发，显示2级菜单导航，在1级菜单的正下方显示。
当2级菜单导航事件被触发，显示3级菜单导航，在2级菜单的右方显示。
当3级菜单导航事件被触发，显示4级菜单导航，在3级菜单的右方显示。
以此类推，不考虑下级菜单显示出界问题。
继续上文中的项目环境，增加一个新HTML文件: page3.html
~ vi D:/workspace/javascript/angular-navbar/page3.html<!DOCTYPE html><html lang="zh-cn"><head> <meta charset="utf-8"> <title>多级导航菜单</title> <meta name="description" content="多级导航菜单"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta name="fragment" content="!" /> <link rel="stylesheet" href="/bower_components/bootstrap/dist/css/bootstrap.min.css" rel="external nofollow" rel="external nofollow" > <link rel="stylesheet" href="/css/main.css" rel="external nofollow" rel="external nofollow" ></head><body ng-app="page2"><div class="container"> <div class="row" ng-controller="NavbarCtrl"> <nav class="navbar navbar-default" role="navigation"> <div class="navbar-header"> <a class="navbar-brand" href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >多级菜单导航</a> </div> <div class="collapse navbar-collapse navbar-ex1-collapse"> <ul class="nav navbar-nav"> <li class="active"><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Link</a></li> <li><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Link</a></li> <li class="dropdown"> <a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="dropdown-toggle" data-toggle="dropdown">Multi Level <b class="caret"></b></a> <ul class="dropdown-menu menu-top"> <li><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Level 1</a></li> <li class="dropdown-submenu"> <a tabindex="-1" href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >More options</a> <ul class="dropdown-menu"> <li><a tabindex="-1" href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Level 2</a> </li> <li class="dropdown-submenu"> <a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >More..</a> <ul class="dropdown-menu"> <li><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Level 3</a> </li> <li><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Level 3</a> </li> <li class="dropdown-submenu"> <a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >More..</a> <ul class="dropdown-menu"> <li><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Level 4</a> </li> <li><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Level 4</a> </li> <li class="dropdown-submenu"> <a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >More..</a> <ul class="dropdown-menu"> <li><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Level 5</a> </li> <li><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Level 5</a> </li> </ul> </li> </ul> </li> </ul> </li> <li><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Level 2</a> </li> <li><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Level 2</a> </li> </ul> </li> <li><a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Level 1</a></li> </ul> </li> </ul> </div> </nav> </div></div><script src="/bower_components/jquery/dist/jquery.min.js"></script><script src="/bower_components/angular/angular.min.js"></script><script src="/bower_components/bootstrap/dist/js/bootstrap.min.js"></script><script src="/bower_components/angular-route/angular-route.min.js"></script><script src="/bower_components/angular-bootstrap/ui-bootstrap-tpls.min.js"></script><script src="/js/app.js"></script></body></html>
新建一个css文件：main.css
~ vi D:/workspace/javascript/angular-navbar/css/main.css.dropdown:hover .menu-top { display: block;}.dropdown-submenu{ position:relative;}.dropdown-submenu > .dropdown-menu{ top:0; left:100%; margin-top:-6px; margin-left:-1px; -webkit-border-radius:0 6px 6px 6px; -moz-border-radius:0 6px 6px 6px; border-radius:0 6px 6px 6px;}.dropdown-submenu:hover > .dropdown-menu{ display:block;}.dropdown-submenu > a:after{ display:block; content:" "; float:right; width:0; height:0; border-color:transparent; border-style:solid; border-width:5px 0 5px 5px; border-left-color:#cccccc; margin-top:5px; margin-right:-10px;}.dropdown-submenu:hover > a:after{ border-left-color:#ffffff;}.dropdown-submenu .pull-left{ float:none;}.dropdown-submenu.pull-left > .dropdown-menu{ left:-100%; margin-left:10px; -webkit-border-radius:6px 0 6px 6px; -moz-border-radius:6px 0 6px 6px; border-radius:6px 0 6px 6px;}刷新一下网页，我们能就看到上面的截图的效果，代码参考：http://firdaus.grandexa.com/2013/09/twitter-bootstrap-3-multilevel-dropdown-menu/
通过HTML和CSS就实现了多级菜单的静态展示效果，如果导航菜单不是经常变化，那么用静态的方式，把代码写死就可以了。但有一些场景，菜单是需要动态生成，比如通过权限控制访问链接，每个用户的权限不一样，那么能看到的菜单选项也就不一样，这个时候就需要做成动态的，用程序去控制菜单的加载和展示。
2. 动态多级菜单实现
有了静态多级导航菜单的HTML代码结构，改写成动态的，其实也不太复杂。
我们需要做2件事：
把导航菜单的数据结构化存储，比如 存放到文件 nav.json。
用Angularjs的API加载nav.json数据，进行展示。
我们先定义一下导航菜单的数据格式，以JSON格式定义，每个菜单项都有3个属性字段
label: 导航菜单项显示的名字。
link: 导航菜单项的跳转链接，可以不定义。
children: 导航菜单项的子菜单，循环对象存储。
{ "label": "levelA", "link": "#", "children": [ { "label": "levelB", "link": "#", "children": [] } ]}下面我们用真实的数据定义导航菜单，以我的金融系统为例。
新建JSON数据文件：nav.json。
~ vi D:/workspace/javascript/angular-navbar/js/nav.json[ { "label": "债券", "children": [ { "label": "可转债", "children": [ {"label": "可转债溢价率分析","link":"#"}, {"label": "可转债NS定价","link":"#"}, {"label": "可转债归因分析","link":"#"}, {"label": "可转债套利实时监控","link":"#"} ] }, { "label": "信用债", "children": [ {"label": "交易所债券监控","link":"#"} ] }, { "label": "利率债","link":"#", "children": [] }, { "label": "国债期货", "children": [ {"label": "国债期货表现分析","link":"#"}, {"label": "国债期货实时套利监控","link":"#"}, {"label": "IRR历史时间序列查询","link":"#"}, {"label": "IRR实时监控","link":"#"} ] } ] }, { "label": "股票", "children": [ { "label": "基本面分析", "children": [ {"label": "上市公司基本面数据查看","link":"#"} ] }, { "label": "量化选股策略", "children": [] } ] }, { "label": "宏观", "children": [ { "label": "宏观数据", "children": [ {"label": "宏观数据概览","link":"#"} ] }, { "label": "宏观经济预测", "children": [] }, { "label": "宏观经济和大类资产表现", "children": [] } ] }]我们看到这个导航菜单的数据，有3级，“债券 >可转债 >可转债归因分析”，那么接下我们就直接实现对三级菜单的编程。创建HTML文件page4.html。
~ vi D:/workspace/javascript/angular-navbar/page4.html<!DOCTYPE html><html lang="zh-cn"><head> <meta charset="utf-8"> <title>多级动态导航菜单</title> <meta name="description" content="多级动态导航菜单"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta name="fragment" content="!" /> <link rel="stylesheet" href="/bower_components/bootstrap/dist/css/bootstrap.min.css" rel="external nofollow" rel="external nofollow" > <link rel="stylesheet" href="/css/main.css" rel="external nofollow" rel="external nofollow" ></head><body ng-app="page4"><div class="container"> <div class="row" ng-controller="NavbarCtrl"> <nav class="navbar navbar-default" role="navigation"> <div class="navbar-header"> <a class="navbar-brand" href="/" rel="external nofollow" >量化投资平台</a> </div> <div class="collapse navbar-collapse navbar-ex1-collapse"> <ul class="nav navbar-nav"> <li ng-repeat="a1 in navbar" class="dropdown"> <a href="?{{ a1.label }}" rel="external nofollow" class="dropdown-toggle" data-toggle="dropdown">{{ a1.label }} <b class="caret"></b></a> <ul class="dropdown-menu menu-top"> <li ng-repeat="a2 in a1.children" class="dropdown-submenu"> <a tabindex="-1" href="?{{ a2.label }}" rel="external nofollow" >{{ a2.label }}</a> <ul ng-show="a2.children.length>0" class="dropdown-menu"> <li ng-repeat="a3 in a2.children"> <a href="?{{ a3.label }}" rel="external nofollow" ng-click="go(a3.link)">{{ a3.label }}</a> </li> </ul> </li> </ul> </li> </ul> </div> </nav> </div></div><script src="/bower_components/jquery/dist/jquery.min.js"></script><script src="/bower_components/angular/angular.min.js"></script><script src="/bower_components/bootstrap/dist/js/bootstrap.min.js"></script><script src="/bower_components/angular-route/angular-route.min.js"></script><script src="/bower_components/angular-bootstrap/ui-bootstrap-tpls.min.js"></script><script src="/js/app.js"></script></body></html>在Angularjs的控制器文件app.js文件中，增加page4的定义。
var page4 = angular.module('page4', ['ui.bootstrap', 'ngRoute']);page4.config(['$routeProvider', '$locationProvider', '$sceProvider', function ($routeProvider, $locationProvider, $sceProvider) { $routeProvider .when('/', {controller: 'DemoCtrl'}) .otherwise({redirectTo: '/'}); $locationProvider.html5Mode(true);}]);page4.controller('NavbarCtrl', function ($scope,$http,$location) { $http.get("/js/nav.json").success(function(json){ $scope.navbar = json; });});page4.controller('DemoCtrl', function () { // nothing});查看一下显示效果，与上面的截图类似。
文章到这里就结束了，已经实现了我的功能需求。但这个话题还有很多可以优化的地方，比如实现无限级的导航菜单，菜单的展示样式替换，展示区间的控制，鼠标动作事件，封装成Angularjs的插件开源项目等。有兴趣的同学，可以我的程序的基础上继续努力，做出优秀的开源项目来。
代码已上传到github：https://github.com/bsspirit/angular-navbar，同学可以根据需要自行下载，也可以直接通过命令下载代码。
git clone https://github.com/bsspirit/angular-navbar.gitcd angular-navbarbower installanywhere
总结
以上所述是小编给大家介绍的AngularJS+Bootstrap3多级导航菜单的实现代码，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对武林网网站的支持！
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