这是我参与11月更文挑战的第22天，活动详情查看：2021最后一次更文挑战
前言
在我们做管理后台亦或是产品流程时，总是需要一个菜单栏或者导航栏来架起我们的产品架构，那么，如何用 vue 实现侧边折叠导航栏呢？接下来将一一介绍。
一、PC端效果
请先看效果演示图，如下图所示：
二、布局构思
1、步骤1
首先我们需要先架构整个页面的布局，撰写 html 、 css 和 js 。
（1）HTML代码
<template>
<div id="main">
<div class="content">
<!-- 左边导航栏 -->
<div class="admin_nav col-lg-3 col-xl-2" v-show="fullWidth">
<div class = "admin_nav_site">
<div class="title">
数据中心后台管理
</div>
<ul v-for="(item,index) in navList" :key="index">
<li @click="handleToTitle(index,item)" @mouseenter="changeTitleColor(index)" @mouseleave="removeTitleColor(index)"
ref="title" :class="{active:currentSort == index}" class="col-lg-12">
<div class="left_icon">
<i :class="'iconfont '+item.className"></i>
</div>
<div class="middle">
{{item.title}}
</div>
<div class="right_icon">
<i :class="'iconfont '+item.close"></i>
</div>
</li>
<li v-for="(it,idx) in item.secMenu" :key="idx" v-show="item.isSubShow" class="active1">
<router-link :to="it.path" tag="a">{{it.name}}</router-link>
</li>
</ul>
</div>
</div>
<!-- 右边内容 -->
<div class="admin_content col-12 col-md-12 col-lg-12 col-xl-10">
<div class="admin_header">
<!-- 导航图标 -->
<div class="H5_item" v-show="!fullWidth">
<i class="iconfont icon-daohanglan" @click="make_menu" class-name="H5-menu"></i>
</div>
<div class="user">
<div class="userHead">
<span>
<img src="../../assets/image/userhead.svg">
</span>
<span>admin</span>
</div>
<div class="logOut">
<i class="iconfont icon-tuichu"></i>
</div>
</div>
</div>
<div class="admin_body">
<keep-alive>
<router-view />
</keep-alive>
</div>
</div>
</div>
</div>
</template>
（2）JS代码
<script>
import axios from 'axios';
export default {
name: 'navigation',
data() {
return {
navList: [{
title: '用户管理',
isSubShow: false,
className: 'icon-guanliyuan1',
close: 'icon-close',
up: 'icon-zhedie',
secMenu: [
{
name: '工号管理',
path: '/home/navigation-one/user'
},
// {
// name: '角色管理',
// path: '/home/navigation-one/role'
// },
// {
// name: '权限管理',
// path: '/home/navigation-one/user'
// },
]
},
{
title: '资源管理',
isSubShow: false,
className: 'icon-ziyuan',
close: 'icon-close',
up: 'icon-zhedie',
secMenu: [
{
name: '我的收藏',
path: '/home/navigation-one/user'
},
{
name: '我的项目',
path: '/home/navigation-one/role'
}
]
},
{
title: '综合管理',
isSubShow: false,
className: 'icon-zonghe',
close: 'icon-close',
up: 'icon-zhedie',
secMenu: [{
name: '划配管理',
path: '/home/navigation-one/user'
},
{
name: '数据信息',
path: '/home/navigation-one/role'
}
]
},
{
title: '系统消息',
isSubShow: false,
className: 'icon-xiaoxi',
close: 'icon-close',
up: 'icon-zhedie',
secMenu: [{
name: '实时动态',
path: '/home/navigation-one/user'
},
{
name: '过去动态',
path: '/home/navigation-one/role'
}
]
}
],
currentSort: 0,
pagetype: "index",
fullWidth: true,
dismenu: true
}
},
methods: {
active(index) {
this.currentSort = index;
},
changeTitleColor(index) {
this.currentSort = index;
},
removeTitleColor(index) {
this.currentSort = null;
},
handleToTitle(ind, item) {
this.navList[ind].isSubShow = !this.navList[ind].isSubShow;
if (this.navList[ind].isSubShow == true) {
this.navList[ind].close = 'icon-zhedie';
} else {
this.navList[ind].close = 'icon-close';
}
}
}
}
</script>
（3）CSS代码
#main {
background: #F0F6FF;
font-size: 0.16rem;
}
#main .content {
display: flex;
flex-direction: row;
}
.content .admin_nav {
min-height: 9.37rem;
max-height: 1.3rem;
padding: 0 !important;
background: #364150;
position: relative;
}
.content .admin_nav .admin_nav_site{
height: 100vh;
}
.content .admin_nav .title {
height: 1.39rem;
line-height: 1.39rem;
background: rgba(63, 73, 86, 1);
color: #FFFFFF;
text-align: center;
font-size: 0.18rem;
display: flex;
justify-content: center;
}
.content .admin_nav .title div {
padding: 0 0.03rem;
}
.content .admin_nav .title div:first-child i {
font-size: 0.18rem;
}
.content .admin_nav ul .active {
background: rgba(68, 81, 99, 1);
}
.content .admin_nav ul .active1 a.router-link-active {
color: #fff;
}
.content .admin_nav ul li {
height: 0.6rem;
display: flex;
flex-direction: column;
justify-content: center;
align-items: center;
font-size: 0.18rem;
}
.content .admin_nav ul li a {
color: #cecdc5;
cursor: pointer;
}
.content .admin_nav ul li:first-child {
font-size: 0.2rem;
height: 0.64rem;
display: flex;
flex-direction: row;
align-items: center;
color: #BEC5C0;
cursor: pointer;
}
.content .admin_nav ul li:first-child div {
width: 100%;
height: 100%;
display: flex;
justify-content: center;
align-items: center;
color: #BEC5C0;
}
.content .admin_nav ul li:first-child .left_icon {
width: 22%;
}
.content .admin_nav ul li:first-child .left_icon i {
color: #1296DB;
}
.content .admin_nav ul li:first-child .middle {
width: 56%;
display: flex;
justify-content: flex-start;
}
.content .admin_nav ul li:first-child .right_icon {
width: 22%;
}
.admin_nav .admin .middle:hover {
color: #fff;
}
.admin_nav .admin .right_icon i:hover {
color: #fff;
}
.admin_nav .admin .middle.router-link-active {
color: #fff;
}
.content .admin_nav_position {
position: absolute;
z-index: 3000;
}
.content .admin_content {
padding: 0 !important;
}
.content .admin_content .admin_header {
width: 100%;
height: 0.6rem;
background: #364150;
display: flex;
flex-direction: row;
align-items: center;
justify-content: space-between;
}
.content .admin_content .admin_header .H5_item {
width: 0.4rem;
height: 0.4rem;
border-radius: 0.2rem;
display: flex;
justify-content: center;
align-items: center;
margin-left: 0.2rem;
}
.content .admin_content .admin_header .H5_item i {
font-size: 0.22rem;
color: #fff;
}
.content .admin_content .admin_header .user {
width: 100%;
display: flex;
align-items: center;
justify-content: flex-end;
}
.content .admin_content .admin_header .user .userHead {
height: 0.6rem;
display: flex;
flex-direction: row;
align-items: center;
color: #fff;
font-size: 0.18rem;
}
.content .admin_content .admin_header .user .userHead span {
padding: 0 0.05rem;
}
.content .admin_content .admin_header .user .userHead span:nth-child(1) {
position: relative;
}
.content .admin_content .admin_header .user .userHead span img {
width: 0.4rem;
height: 0.4rem;
border-radius: 50%;
}
.content .admin_content .admin_header .user .userHead span input {
width: 0.4rem;
height: 0.4rem;
position: absolute;
overflow: hidden;
opacity: 0;
cursor: pointer;
}
.content .admin_content .admin_header .user .logOut {
color: #fff;
margin-left: 0.12rem;
margin-right: 0.5rem;
}
.content .admin_content .admin_header .user .logOut i {
color: #1296DB;
font-size: 0.24rem;
cursor: pointer;
}
.toggle-cart-enter-active {
transition: all 0.4s linear;
}
.toggle-cart-leave-active {
transition: all 0.4s linear;
}
.toggle-cart-enter {
transform: translateX(-200%);
}
.toggle-cart-leave-active {
transform: translateX(-200%);
}
2、步骤2
撰写完基本网页布局和样式后，对部分细节进行剖析。
（1）动态绑定路径
<router-link :to="it.path" tag="a">{{it.name}}</router-link>
（2）一级菜单，标题及折叠符号
①通过 @mouseenter 和 @mouseleave 事件，当鼠标移入和移出时，改变标题区域背景颜色。
②通过 @click 事件，当鼠标点击时，显示二级菜单列表。
③利用 :class 动态绑定类名，触发 active 方法，修改折叠符号状态；绑定图标类名，通过遍历，修改对应图标。
<ul v-for="(item,index) in navList" :key="index">
<li @click="handleToTitle(index,item)" @mouseenter="changeTitleColor(index)" @mouseleave="removeTitleColor(index)" ref="title" :class="{active:currentSort == index}" class="col-lg-12">
<div class="left_icon">
<i :class="'iconfont '+item.className"></i>
</div>
<div class="middle">
{{item.title}}
</div>
<div class="right_icon">
<i :class="'iconfont '+item.close"></i>
</div>
</li>
<li v-for="(it,idx) in item.secMenu" :key="idx" v-show="item.isSubShow" class="active1">
<router-link :to="it.path" tag="a">{{it.name}}</router-link>
</li>
</ul>
3、步骤3
菜单栏完成后，在网页端能进行查看，但是还需做一个手机端适配，这样就达到两端同步适应的效果。实现如下：
①对左边导航栏再撰写第二套代码，并绑定好对应的参数实现显示和隐藏。
②运用 vue 已有的 transition ，绑定 name 值，实现动画效果绑定。
（1）HTML代码
<!-- 移动端导航栏 -->
<transition name="toggle-cart">
<div class="admin_nav admin_nav_position col-8 col-md-5 col-lg-3 col-xl-3" v-show="!fullWidth&&!dismenu">
<div class="title">
<div v-show="!fullWidth">
<i class="iconfont icon-daohanglan" @click="make_menu" class-name="H5-menu"></i>
</div>
<div>数据中心后台管理</div>
</div>
<ul v-for="(item,index) in navList" :key="index">
<li @click="handleToTitle(index,item)" @mouseenter="changeTitleColor(index)" @mouseleave="removeTitleColor(index)" ref="title" :class="{active:currentSort == index}">
<div class="left_icon">
<i :class="'iconfont '+item.className"></i>
</div>
<div class="middle">
{{item.title}}
</div>
<div class="right_icon">
<i :class="'iconfont '+item.close"></i>
</div>
</li>
<li v-for="(it,idx) in item.secMenu" :key="idx" v-show="item.isSubShow" class="active1">
<router-link :to="it.path" tag="a">{{it.name}}</router-link>
</li>
</ul>
</div>
</transition>
（2）JS代码
mounted() {
window.onresize = () => { //监听屏幕变化
this.page_width();
};
this.page_width();
}，
methods: {
make_menu() { //点击导航图标
this.dismenu = !this.dismenu;
},
page_width() { //获取屏幕宽度
var screenWidth = window.screen.width;
if (screenWidth <= 1024) {
this.fullWidth = false;
} else {
this.fullWidth = true;
}
}
}
三、手机端效果
最后来看下手机端效果：
四、小细节
1、 css 样式中的 rem 换算成 px 为对应的 rem 值 *1 00,如：font-size:0.24rem; => font-size:24px;
**2、**文章中涉及到的 iconfont 类名是因为引用了阿里图标，如遇到不知道如何引用的可以翻阅博文→ vue项目中引入阿里图标iconfont_moandaylab
**3、**关于 router-link 对应的跳转，如有小伙伴不太清楚如何使用 vue-router 配置路由的可以翻阅博文→vue项目中使用vue-router进行路由配置及嵌套多级路由_moandaylab
Ending(〃'▽'〃)！
