文章目录

前情提要
- 小程序的包结构
- app.json声明包结构
- 独立分包
- - 声明独立分包
- 分包预下载
- - 声明分包预下载
搭建静态资源服务器
小程序项目
- app.json
- 主包
- - app.wxss
  - app.js
  - pages/search/search.json
  - pages/search/search.wxml
  - pages/search/search.wxss
  - pages/search/search.js
  - pages/login/login.json
  - pages/login/login.wxml
  - pages/login/login.wxss
  - pages/login/login.js
- 分包
- - music-package/pages/index/index.json
  - music-package/pages/index/index.wxml
  - music-package/pages/index/index.wxss
  - music-package/pages/index/index.js
  - music-package/pages/music/music.json
  - music-package/pages/music/music.wxml
  - music-package/pages/music/music.wxss
  - music-package/pages/music/music.js
相关链接

前情提要

某些情况下，需要对小程序进行分包。分包后的小程序必定有一个主包，一个或多个分包。
小程序启动时，默认下载 主包并启动主包内页面，只有当进入分包内某个页面时，客户端才会下载对应分包，然后展示分包页面，即分包是按需进行加载的。

目前小程序分包大小有如下限制：

整个小程序所有分包大小不超过 20M。
主包或单个分包大小不超过 2M。

小程序的包结构

小程序的包结构如下。其中，文件夹pages下的是主包，文件夹music-package下的是分包。

app.json声明包结构

在app.json中声明包结构。其中， pages 字段声明了主包，subpackages 字段声明了分包结构。subpackages的值是一个数组，数组的每个元素是一个对象，该对象包含如下属性：

root，分包的根目录，string类型。
name，分包别名，分包预下载时可以使用，string类型。
pages，分包页面路径，相对于分包根目录，即相对于root。pages是一个字符串数组。
independent，是否使用独立分包，布尔类型。

独立分包

独立分包是小程序中一种特殊类型的分包，它可以独立于主包和其他分包运行。
一个小程序可以有多个独立分包。
当小程序从主包页面或者其他分包页面启动时，需要先下载主包。而当进入独立分包页面时，不需要下载主包，因为独立分包是独立于主包和其他分包运行的。

声明独立分包

app.json中的subpackages字段下的各配置项的 independent 字段，设置为 true，即为独立分包。

分包预下载

分包预下载，即在进入小程序页面时，预先下载可能需要的分包。

声明分包预下载

在app.json的 preloadRule 下声明分包预下载。preloadRule的值是一个对象，该对象中的内容以key-value的形式出现。其中，key是某个分包页面路径，value是一个对象，该对象包含如下属性：

packages，是一个数组，每个元素是进入页面后预下载分包的root或name。另外，__APP__代表主包。如packages:["package_a_root","package_b_name","__APP__"]。
network，表示在指定网络下预加载。string类型，支持以下两个值：
- "all"，表示不限网络。
- "wifi"，表示，仅wifi下预下载。

搭建静态资源服务器

全局安装serve：npm install -g serve
在任何你想的地方新建文件夹：resources。resources下新建文件夹：images，用于存放静态图片资源；resources下新建文件夹：videos，用于存放视频文件；resources下新建文件夹：audios，用于存放音频文件。
启动服务器：serve resources。

小程序项目

代码涉及的主要文件有：

app.json
app.wxss
app.js
pages/search/search.json
pages/search/search.wxml
pages/search/search.wxss
pages/search/search.js
pages/login/login.json
pages/login/login.wxml
pages/login/login.wxss
pages/login/login.js
music-package/pages/index/index.json
music-package/pages/index/index.wxml
music-package/pages/index/index.wxss
music-package/pages/index/index.js
music-package/pages/music/music.json
music-package/pages/music/music.wxml
music-package/pages/music/music.wxss
music-package/pages/music/music.js

app.json

{"pages": ["pages/search/search","pages/login/login"],"subPackages": [ {"root": "music-package","pages": ["pages/index/index","pages/music/music"]}],"window": {"navigationBarBackgroundColor": "#fff","navigationBarTitleText": "首页","navigationBarTextStyle": "black"},"tabBar": {"position": "top","color": "#000000","selectedColor": "#971a22","backgroundColor": "#ffffff","list": [{"pagePath": "pages/search/search","text": "搜索音乐"},{"pagePath": "pages/login/login","text": "个人登录"}]},"requiredBackgroundModes": ["audio"],"style": "v2","sitemapLocation": "sitemap.json"
}

主包

app.wxss

page{height: 100%;
}

app.js

App({globalData:{isPlayGlobal:false,   //当前是否有歌曲在播放musicIdGlobal:''     //当前正在播放的歌曲是哪首}
})

pages/search/search.json

{"usingComponents": {},"navigationBarTitleText": "搜索"
}

pages/search/search.wxml

<view class="search-container"><view class="header"><view class="input-box"><image src="/static/images/search.png"></image><input type="text" placeholder="你想听的 这里都有~" placeholder-style="font-swxize:27rpx"bindinput="handleInput" value="{{keyword}}"/><image src="/static/images/cross.png" bindtap="removeKeyword" hidden="{{!keyword}}"></image></view></view><block wx:if="{{keyword}}"><view class="search-container"><view class="search-title">搜索"{{keyword}}"</view><view class="search-list"><view class="search-item" wx:for="{{searchList}}" wx:key="id"><image src="/static/images/search.png"></image><view class="content">{{item.content}}</view></view></view></view></block><block wx:else><view class="history-container" wx:if="{{historyList.length}}"><view class="history-header"><view class="history-title">搜索历史</view><image src="/static/images/delete.png" bindtap="deleteHistory"></image></view><view class="history-list"><text class="history-item" wx:for="{{historyList}}" wx:key="*this">{{item}}</text></view></view><view class="hot-container"><view class="hot-title">热搜榜</view><view class="hot-list"><view class="hot-item" wx:for="{{hotList}}" wx:key="id"><text class="order" style="{{(index===0 || index ===1 || index==2) && 'color:#d81e06' }}">{{index+1}}</text><text class="name">{{item.keyword}}</text><image wx:if="{{item.iconUrl}}" src="{{item.iconUrl}}"></image></view></view></view></block>
</view>

pages/search/search.wxss

.search-container{padding: 20rpx;
}
.input-box{background: #eee;border-radius: 28rpx;display: flex;align-items: center;
}
.input-box input{height: 60rpx;line-height: 60rpx;flex: 1;font-size: 27rpx;
}
.input-box image{width: 36rpx;height: 36rpx;padding: 0 20rpx;
}
.hot-container{margin: 20rpx 0;
}
.hot-container .hot-title{font-size: 26rpx;font-weight:550;
}
.hot-list{padding: 10rpx 0 ;
}
.hot-item{height: 60rpx;line-height: 60rpx;display: flex;align-items: center;margin-bottom: 20rpx;
}
.hot-item .order{display: inline-block;width: 40rpx;height: 60rpx;line-height: 60rpx;text-align: center;margin-right: 30rpx;color: #888;
}
.hot-item .name{font-weight: 550;
}
.hot-item image{width: 48rpx;height: 48rpx;margin-left: 20rpx;
}
.search-container .search-title{color: #d81e06;height: 80rpx;line-height: 80rpx;font-size: 28rpx;
}
.search-item{display: flex;align-items: center;height: 80rpx;line-height: 80rpx;
}
.search-item image{width: 28rpx;height: 28rpx;margin-right: 20rpx;
}
.search-item .content{flex:1;color: #666;font-size: 28rpx;
}
.history-container{margin-top: 20rpx;
}
.history-header {display: flex;align-items: center;justify-content: space-between;
}
.history-header .history-title{font-size: 26rpx;font-weight:550;
}
.history-header image{width: 36rpx;height: 36rpx;
}
.history-list{display: flex;flex-wrap: wrap;padding: 20rpx 0;
}
.history-item{font-size: 26rpx;height: 36rpx;line-height: 36rpx;text-align: center;padding: 6rpx 16rpx;background: #eee;border-radius: 16rpx;margin: 0 20rpx 20rpx 0;
}

pages/search/search.js

const host = "http://localhost:3000"
let timer = null;Page({data:{hotList:[],keyword:'',searchList:[],historyList:[]},onLoad(){this.getHotList();const historyList = wx.getStorageSync('historyList');if(historyList){this.setData({historyList})}},getHotList(){const result = [{id:"001",keyword:"周杰伦",iconUrl:host+"/images/hot-fill.png"},{id:"002",keyword:"最伟大的作品"},{id:"003",keyword:"林俊杰"},{id:"004",keyword:"孤勇者"},{id:"005",keyword:"再见莫妮卡"},{id:"006",keyword:"陈奕迅"},{id:"007",keyword:"李荣浩"},{id:"008",keyword:"毛不易"}]this.setData({hotList:result})},handleInput(event){const keyword = event.detail.value.trim();if(!keyword) {this.setData({keyword:''});return;}this.throttle(this.getSearchList,500);const {historyList} = this.data;const index = historyList.indexOf(keyword);if(index > -1){historyList.splice(index,1);}const newHistoryList = [keyword,...historyList].slice(0,10) //最多显示10条搜索历史，且后来者居上wx.setStorageSync("historyList",newHistoryList)this.setData({keyword,historyList:newHistoryList});},throttle(fn,delay){if(timer != null) return;timer = setTimeout(() => {timer = nullfn();},delay) },getSearchList(){const result = [{id:"001",content:"周杰伦"},{id:"002",content:"周杰伦 最伟大的作品"},{id:"003",content:"周杰伦 爷爷泡的茶"},{id:"004",content:"周杰伦 珊瑚海"},{id:"005",content:"周杰伦 夜的第七章"},{id:"006",content:"周杰伦 说好不哭"},{id:"007",content:"周杰伦 等你下课"},{id:"008",content:"周杰伦 我是如此相信"}]this.setData({searchList:result})},removeKeyword(){this.setData({keyword:'',searchList:[]})},deleteHistory(){this.setData({historyList:[]});wx.removeStorageSync('historyList');}
})

pages/login/login.json

{"navigationBarTitleText": "登录"
}

pages/login/login.wxml

<view class="login-container"><view class="list"><view class="item"><input type="text" data-type="username" bindinput="handleInput" placeholder="用户名" /></view><view class="item"><input type="text" password data-type="password" bindinput="handleInput" placeholder="密码" /></view></view><button size="mini" bindtap="login">登录</button>
</view>

pages/login/login.wxss

.login-container{padding: 20rpx;
}
.list{margin: 20rpx auto;
}
.item{margin: 12rpx 0;padding: 0 20rpx;border: 1px solid #ddd;border-radius: 6rpx;
}
.item input{width: 100%;height: 60rpx;font-size: 28rpx;
}
button{font-weight: normal;font-size: 28rpx!important;color: #fff;background: #0149af;
}

pages/login/login.js

Page({data:{username:"",password:""},handleInput(e){const type = e.target.dataset.type;this.setData({[type]:e.detail.value})},login(){const {username,password} = this.data;if(!username){wx.showToast({title: '请输入您的用户名',icon:'error'})return;}if(!password){wx.showToast({title: '请输入您的密码',icon:'error'})return;}this.sendLoginRequest();wx.showToast({title: '登录成功',success:() => {setTimeout(() => {wx.reLaunch({url: '/music-package/pages/index/index',})},300)}})},sendLoginRequest(){const userInfo = {avatarUrl:"/static/images/avatar.png",nickname:"Duck先生"}wx.setStorageSync("userInfo",JSON.stringify(userInfo));}
})

分包

music-package/pages/index/index.json

{"usingComponents": {},"navigationBarTitleText": "音乐","navigationBarBackgroundColor": "#624d2e","navigationBarTextStyle": "white"
}

music-package/pages/index/index.wxml

<view class="index-container"><view class="header"><image src="/static/images/icon-play-square.png"></image><text>播放全部</text><text>{{musicList.length}}</text></view><scroll-view class="music-list" enable-flex scroll-y ><view class="music-item" wx:for="{{musicList}}" wx:key="id" bindtap="handleTap" data-musicindex="{{index}}" data-musicitem="{{item}}"><view class="music-index">{{index+1}}</view><image class="music-image" src="{{item.picUrl}}"></image><view class="music-info"><view class="musci-name">{{item.name}}</view><view class="music-author">{{item.author}}</view></view><image class="btn-more" src="/static/images/icon-more.png"></image></view></scroll-view>
</view>

music-package/pages/index/index.wxss

.index-container{padding: 20rpx;background:#624d2e;
}
.header{display: flex;align-items: center;
}
.header image{width: 28rpx;height: 28rpx;margin-right: 20rpx;
}
.header text{color: #fff;height: 28rpx;line-height: 28rpx;margin-right: 20rpx;font-size: 28rpx;
}
.music-list{margin-top: 20rpx;color: #fff;height: calc(100vh - 88rpx);
}
.music-item{display: flex;align-items: center;height: 100rpx;margin: 20rpx 0;position: relative;
}
.music-item .music-index{width: 50rpx;font-size: 28rpx;color: #aaa;
}
.music-item .music-image{width: 80rpx;height: 80rpx;border-radius: 6rpx;margin-right: 20rpx;
}
.music-item .music-info{display: flex;flex-direction: column;
}
.music-item .music-info .music-author{font-size: 24rpx;color: #aaa;margin-top: 10rpx;
}
.music-item .btn-more{width: 36rpx;height: 36rpx;position: absolute;right: 0;
}

music-package/pages/index/index.js

import PubSub from "pubsub-js";
const host = "http://localhost:3000";Page({data:{musicList:[], //歌曲列表musicindex:0  //进入某首歌曲后，记录该歌曲在列表中的索引},onLoad(){this.getDataFromServer();//接收消息，接收来自页面pages/music/music的消息，根据“上一首”or“下一首”，确定当前应该显示哪首歌曲PubSub.subscribe("switchsong",(msgName,type) => {// console.log(msgName,type);let {musicindex,musicList} = this.data;if(type === "prev"){if(musicindex===0) {musicindex = musicList.length-1;}else{musicindex--;}}else if(type === "next"){if(musicindex === musicList.length-1){musicindex = 0;}else{musicindex++;}}this.setData({musicindex});const music = musicList[musicindex];//发送消息，告诉页面pages/music/music，告诉它切换完成后的歌曲的详细消息。PubSub.publish("refreshmusic",music);})},getDataFromServer(){const result = [{id:"001",name:"滂沱大雨里","author":"李若溪","picUrl":host+"/images/滂沱大雨里.jpg","url":host+"/audios/滂沱大雨里.mp3",duration:161000},{id:"002",name:"Last Dance","author":"伍佰","picUrl":host+"/images/Last Dance.jpg","url":host+"/audios/Last Dance.mp3",duration:271000},{id:"003",name:"国王与乞丐","author":"华晨宇","picUrl":host+"/images/国王与乞丐.jpg","url":host+"/audios/国王与乞丐.mp3",duration:178000},{id:"004",name:"奇洛李维斯回信","author":"薛凯琪","picUrl":host+"/images/奇洛李维斯回信.jpg","url":host+"/audios/奇洛李维斯回信.mp3",duration:243000},{id:"005",name:"红日","author":"李克勤","picUrl":host+"/images/红日.jpg","url":host+"/audios/红日.mp3",duration:291000},{id:"006",name:"快乐崇拜","author":"潘玮柏 张韶涵","picUrl":host+"/images/快乐崇拜.jpg","url":host+"/audios/快乐崇拜.mp3",duration:329000},{id:"007",name:"门没锁","author":"黄品冠","picUrl":host+"/images/门没锁.jpg","url":host+"/audios/门没锁.mp3",duration:233000},{id:"008",name:"就是爱你","author":"陶喆","picUrl":host+"/images/就是爱你.jpg","url":host+"/audios/就是爱你.mp3",duration:340000},{id:"009",name:"快乐的小青蛙","author":"刘士鸣","picUrl":host+"/images/快乐的小青蛙.jpg","url":host+"/audios/快乐的小青蛙.mp3",duration:130000},{id:"0010",name:"友情岁月","author":"陈小春 郑伊健 谢天华 林晓峰 钱嘉乐","picUrl":host+"/images/友情岁月.jpg","url":host+"/audios/友情岁月.mp3",duration:209000},{id:"0011",name:"温柔","author":"五月天","picUrl":host+"/images/温柔.jpg","url":host+"/audios/温柔.mp3",duration:269000}];this.setData({musicList:result});},handleTap(event){const {musicitem,musicindex} = event.currentTarget.dataset;this.setData({musicindex})wx.navigateTo({url: '/music-package/pages/music/music?musicitem='+JSON.stringify(musicitem),})}
})

music-package/pages/music/music.json

{"usingComponents": {},"navigationBarBackgroundColor": "#2f434e","navigationBarTitleText": "音乐详情","navigationBarTextStyle": "white"
}

music-package/pages/music/music.wxml

<view class="music-container"><view class="music-name">{{music.name}}</view><view class="music-author">{{music.author}}</view><image class="arm {{isPlay&&'arm-reset'}}" src="/static/images/arm.png"></image><view class="disc-container {{isPlay&&'disc-animate'}}"><image class="disc" src="/static/images/disc.png"></image><image class="music-image" src="{{music.picUrl}}"></image></view><view class="progress-container"><text class="current-time">{{fmtCurrentTime}}</text><view class="bar-box"><view class="current-progress" style="width:{{currentWidth}}rpx"><view class="progress-circle"></view></view></view><text class="duration">{{fmtDuration}}</text></view><view class="player"><view class="btns"><image class="loop-btn" src="/static/images/loop.png"></image><image class="prev-btn" src="/static/images/prev.png" id="prev" bindtap="handleSwitch"></image><image class="play-btn" src="{{isPlay?'/static/images/stop.png':'/static/images/play.png'}}" bindtap="handlePlay"></image><image class="next-btn" src="/static/images/next.png" id="next" bindtap="handleSwitch"></image><image class="list-btn" src="/static/images/list.png"></image></view></view>
</view>

music-package/pages/music/music.wxss

.music-container{height: 100%;display: flex;flex-direction: column;align-items: center;background: #2f434e;position: relative;
}
.music-container .music-name{margin: 10rpx 0;color: #fff;font-size: 36rpx;
}
.music-container .music-author{color: #bbb;font-size: 28rpx;margin: 6rpx 0;
}
.music-container .arm{width:204rpx;height: 358rpx;position: relative;left: 72rpx;z-index: 99;transform: rotate(-15deg);transform-origin: 30rpx 30rpx;transition: transform .7s linear;
}
.disc-container{position: relative;top: -128rpx;width: 490rpx;height: 490rpx;
}
.disc-container .disc{width: 100%;height: 100%;
}
.disc-container .music-image{width: 270rpx;height: 270rpx;border-radius: 100%;position: absolute;left: 0;right: 0;top: 0;bottom: 0;margin: auto;
}
.music-container .arm-reset{transform: rotate(0deg);
}
.disc-animate{animation: rotate 2.5s 1s linear infinite;
}
@keyframes rotate{from{transform: rotate(0deg);}to{transform: rotate(360deg);}
}
.player{width: 100%;position: absolute;bottom: 60rpx;
}
.btns{display: flex;align-items: center;justify-content: space-evenly;
}
.btns image{width: 36rpx;height: 36rpx;
}
.btns .play-btn,.btns .stop-btn{width: 90rpx;height: 90rpx;
}
.progress-container {width: 100%;display: flex;justify-content: space-around;align-items: center;
}
.progress-container .bar-box{width: 456rpx;height: 4rpx;line-height: 4rpx;background: #888;
}
.bar-box .current-progress{position: relative;height: 4rpx;line-height: 4rpx;background: #fff;
}
.progress-circle{width: 16rpx;height: 16rpx;border-radius: 50%;background: #fff;position: absolute;right: -16rpx;top: -6rpx;
}
.progress-container text{color: #ccc;font-size: 22rpx;margin: 0 40rpx;
}

music-package/pages/music/music.js

import PubSub from "pubsub-js";
import moment from 'moment';
const appInstance = getApp();Page({data:{isPlay:false,music:{},fmtDuration:"00:00",fmtCurrentTime:"00:00",currentWidth:0},onLoad(options){const music = JSON.parse(options.musicitem);let fmtDuration = moment(music.duration).format("mm:ss");this.setData({music,fmtDuration})const {isPlayGlobal,musicIdGlobal} = appInstance.globalData;const {id} = this.data.music;if(isPlayGlobal && musicIdGlobal === id) {this.setData({isPlay:true});}this.bam = wx.getBackgroundAudioManager();this.bam.onPlay(() => {this.setData({isPlay:true})appInstance.globalData.isPlayGlobal = true;appInstance.globalData.musicIdGlobal = this.data.music.id;})this.bam.onPause(() => {this.setData({isPlay:false})appInstance.globalData.isPlayGlobal = false;})this.bam.onStop(() => {this.setData({isPlay:false})appInstance.globalData.isPlayGlobal = false;})this.bam.onEnded(() => {// this.setData({isPlay:false});// appInstance.globalData.isPlayGlobal = false;// 音乐自然播放结束，则切换至下一首PubSub.publish("switchsong","next");//接收消息，接收来自pages/index/index的消息，显示切换后的歌曲详情const eventId = PubSub.subscribe("refreshmusic",(msgName,music) => {PubSub.unsubscribe(eventId);this.setData({music})this.musicControl();const fmtDuration = moment(this.data.music.duration).format("mm:ss");this.setData({fmtDuration,fmtCurrentTime:"00:00"})})  })this.bam.onTimeUpdate(() => {const currentWidth = Math.floor(456 * this.bam.currentTime / this.bam.duration);const fmtCurrentTime = moment(this.bam.currentTime * 1000).format("mm:ss");this.setData({currentWidth,fmtCurrentTime});})},handlePlay(){const isPlay = !this.data.isPlay;this.setData({isPlay});this.musicControl();},musicControl(){const {isPlay} = this.data;if(isPlay){this.bam.src = this.data.music.url;this.bam.title = this.data.music.name;}else{this.bam.pause();}},handleSwitch(event){const type = event.target.id;//发送消息，告诉pages/index/index：切上一首还是下一首。prev代表切上一首，next代表切下一首。PubSub.publish("switchsong",type);//接收消息，接收来自pages/index/index的消息，显示切换后的歌曲详情const eventId = PubSub.subscribe("refreshmusic",(msgName,music) => {PubSub.unsubscribe(eventId);this.setData({music})this.musicControl();})}
})

微信小程序的分包加载