文章目录

前情提要
- pubsubjs实现页面通信
- moment.js实现时间格式化
- BackgroundAudioManager
小程序项目
- app.json
- app.wxss
- app.js
- pages/index/index.json
- pages/index/index.wxml
- pages/index/index.wxss
- pages/index/index.js
- pages/music/music.json
- pages/music/music.wxml
- pages/music/music.wxss
- pages/music/music.js
相关链接

前情提要

pubsubjs实现页面通信

npm install --save pubsub-js，安装第三方库pubsub-js。
import PubSub from "pubsub-js"，引入第三方库pubsub。
订阅消息：id = PubSub.subscribe(消息名,callback)，且callback的第一个形参默认是消息名，后面则是开发者自己传入的参数。
发布消息：PubSub.publish(消息名,开发者的参数)。
取消订阅：PubSub.unsubscribe(id)。

moment.js实现时间格式化

本例会使用第三方库moment.js来格式化时间。

安装依赖。npm install --save moment。
微信开发者工具中，工具>构建npm。
页面中引入并使用moment。
import moment from "moment";
moment(时间).format(格式);

BackgroundAudioManager

BackgroundAudioManager，是全局唯一的背景音频管理器。小程序切入后台，如果音频处于播放状态，可以继续播放。但是后台状态不能通过调用API操纵音频的播放状态。
从微信客户端6.7.2版本开始，如果需要小程序切后台后继续播放音频，需要在全局配置文件 app.json 中配置 requiredBackgroundModes 属性，如："requiredBackgroundModes": ["audio"]。

BackgroundAudioManager实例，可以通过 wx.getBackgroundAudioManager() 获取。BackgroundAudioManager实例具有如下属性和方法：

title，音频标题，必填。
src，音频的数据源，默认值是空字符串，非必填。但是，只有设置了src时，音频才会自动播放。
duration，当前音频的长度，number类型，单位为s，即秒。
currentTime，当前音频的播放位置，number类型，单位为s，即秒。
play()，播放音乐。
pause()，暂停音乐。
onPlay(function callback)，监听背景音频播放事件。
onPause(function callback)，监听背景音频暂停事件。
onStop(function callback)，监听背景音频停止事件。
onEnded(function callback)，监听背景音频自然播放结束事件。
onTimeUpdate(function callback)，监听背景音频播放进度更新事件。

小程序项目

代码涉及的主要文件有：

app.json
app.wxss
app.js
pages/index/index.json
pages/index/index.wxml
pages/index/index.wxss
pages/index/index.js
pages/music/music.json
pages/music/music.wxml
pages/music/music.wxss
pages/music/music.js

app.json

{"pages": ["pages/index/index","pages/music/music"],"window": {"navigationBarBackgroundColor": "#624d2e","navigationBarTitleText": "首页","navigationBarTextStyle": "white"},"requiredBackgroundModes": ["audio"],"style": "v2","sitemapLocation": "sitemap.json"
}

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/index/index.json

{"usingComponents": {},"navigationBarTitleText": "播放列表"
}

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>

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;
}

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: '/pages/music/music?musicitem='+JSON.stringify(musicitem),})}
})

pages/music/music.json

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

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>

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;
}

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();})}
})

微信小程序实现音乐播放器（5）