@TOC

前言

前面一篇文章Vue开发历程—音乐播放器，实现了播放音乐，以及基本的布局。但是进度条没有实现同步，本文即介绍进度条的实现。

一、效果图

二、心路历程

1、elementUI 滑块的使用

 <div class="block" style="margin-top:5px">
	<el-slider v-model="value" @change="updateSlideTime()" :format-tooltip="formatTooltip"></el-slider>
 </div>

2、JS的编写

进度条的状态是实时的，也就是每一秒每一刻都要变化，如何实现这一功能？
首先需要写一个方法，每30ms更新一次状态，同时在组件挂载完成的时候调用这个方法，从而实现了每30ms，即更新进度条的数值。
通过refs可以获得audio这个标签，这个标签上有duration（时长），currentTime（当前时间）这两个属性，通过这两个属性，可以计算出来进度的占比。

 updateSongsTime: function () {
            const timer = setInterval(() => {
                const music = document.getElementById("m_mp3")||null;
                if (music != null) {
                    this.currentTime = music.currentTime;
                    this.duration = music.duration;
                    this.persent = (this.currentTime / this.duration) * 100;
                }

            }, 30);

mounted() {
        this.songNum = this.songNames.length;
        const music = this.$refs.player;
        this.updateSongsTime();

    }

同时也需要在MusicPlayer.vue组件里面如法炮制，获取父组件的值从而实时更新滑块的状态，因为滑块是写在MusicPlayer组件里面了，但是歌曲的播放在父组件Player.vue里，所以也是用到了组件的通信。

3、时间的转化

由于currentTime返回来的是总秒数，而音乐播放器一般都是分:秒这样的格式，所以通过一些简单的数学计算（除以60求分，对60取余求秒）来进行对时长的格式化处理。采用了三目运算符，还对不足10的时间进行了处理，即小于10的数值前面自动补0

formatTooltip()
        {
            return Math.trunc(this.$parent.currentTime/60)+":"+((Math.trunc(this.$parent.currentTime%60)<10)?("0"+Math.trunc(this.$parent.currentTime%60)):Math.trunc(this.$parent.currentTime%60));
        }

#源代码

代码如下：
Player.vue

<template>
    <div class="player_div1">
        <transition name="open" mode="out-in">
            <component v-bind:is="view" @hello="changeSlideState" @play="changePlayState" @lastSongs="lastSongs"
                @nextSongs="nextSongs" @changeSongsTime="changeSongsTime"></component>
        </transition>
        <audio class="m_mp3" id="m_mp3" :src="this.songNames[this.index].Url" autoplay loop ref="player" controls
            style="display:none">

        </audio>
    </div>

</template>

<script>
import HidePlayer from '@/part/HidePlayer'
import MusicPlayer from '@/part/MusicPlayer'
export default {
    name: 'Player',
    data() {
        return {
            view: MusicPlayer,
            isClose: false,
            isShow: true,
            isRun: 'come',
            index: 0,
            songNum: 2,
            currentTime: 0,
            duration: 0,
            persent: 0,
            songNames: [
                {
                    id: 6,
                    name: '庐州月-许嵩',
                    Url: require('@/assets/庐州月.mp3'),
                    png: require('@/assets/庐州月.png'),
                },
                {
                    id: 7,
                    name: '燕归巢-许嵩',
                    Url: require('@/assets/燕归巢.mp3'),
                    png: require('@/assets/燕归巢.jpg'),
                },
                {
                    id: 1,
                    name: '张韶涵-篇章',
                    Url: require('@/assets/张韶涵-篇章.mp3'),
                    png: require('@/assets/篇章.png'),
                },
                {
                    id: 2,
                    name: '爱就一个字 抒情版',
                    Url: require('@/assets/爱就一个字 抒情版.mp3'),
                    png: require('@/assets/爱就一个字.png'),
                },
                {
                    id: 3,
                    name: '最伟大的作品-周杰伦',
                    Url: require('@/assets/最伟大的作品-周杰伦.mp3'),
                    png: require('@/assets/周杰伦.jpg'),
                },
                {
                    id: 4,
                    name: '等你下课 (with 杨瑞代)-周杰伦',
                    Url: require('@/assets/等你下课 (with 杨瑞代)-周杰伦.mp3'),
                    png: require('@/assets/等你下课.png'),
                },
                {
                    id: 5,
                    name: '告白气球-周杰伦',
                    Url: require('@/assets/告白气球-周杰伦.mp3'),
                    png: require('@/assets/告白气球.png'),
                },
                {
                    id: 6,
                    name: '还在流浪-周杰伦',
                    Url: require('@/assets/还在流浪-周杰伦.mp3'),
                    png: require('@/assets/还在流浪.png'),
                },
            ]
        }
    },
    components: {
        HidePlayer,
        MusicPlayer
    },
    methods: {
        changeSlideState() {
            this.isClose = !this.isClose;
            if (this.isClose) {
                this.view = HidePlayer;
            } else {
                this.view = MusicPlayer;
            }
        },
        changePlayState() {
            if (!this.isShow) {
                this.isShow = true;
                this.isRun = "come";
                document.getElementById("m_mp3").pause();
            } else {
                this.isShow = false;
                this.isRun = "go";
                var my_mp3 = document.getElementById("m_mp3");
                my_mp3.play();


            }
        },
        nextSongs() {
            if (this.isShow) {
                this.isShow = false;
                this.isRun = "go";
            }
            this.index = (this.index + 1) % this.songNum;
        },
        lastSongs() {
            if (this.isShow) {
                this.isShow = false;
                this.isRun = "go";
            }
            if (this.index == 0) {
                this.index = this.songNum - 1;
            } else {
                this.index = this.index - 1;
            }

        },
        changeSongsTime(value) {
            const music = document.getElementById("m_mp3");
            music.currentTime = value / 100 * music.duration;

        }
        ,
        updateSongsTime: function () {
            const timer = setInterval(() => {
                const music = document.getElementById("m_mp3")||null;
                if (music != null) {
                    this.currentTime = music.currentTime;
                    this.duration = music.duration;
                    this.persent = (this.currentTime / this.duration) * 100;
                }

            }, 30)
        }
    }, mounted() {
        this.songNum = this.songNames.length;
        const music = this.$refs.player;
        this.updateSongsTime();

    }

}
</script>

<style scoped>
.open-enter-active {
    animation: slide-in linear 0.5s;
}

.open-leave-active {
    animation: slide-in reverse linear 0.5s;
}

@keyframes slide-in {
    from {
        transform: translateX(-100%);
    }

    to {
        transform: translateX(0%);
    }
}


</style>

MusicPlayer.vue

<template>
    <div class="music">
        <!-- 占位 -->
        <div class="m_hold">

        </div>
        <div class="m_img">
            <img :src="this.$parent.songNames[this.$parent.index].png" width="90px" :class="this.$parent.isRun">
        </div>
        <!-- 歌曲信息 -->
        <div class="m_text">
            {{ this.$parent.songNames[this.$parent.index].name }}
            <div class="block" style="margin-top:5px">
               <el-slider v-model="value" @change="updateSlideTime()" :format-tooltip="formatTooltip"></el-slider>
            </div>
            
        </div>
        <!-- 音乐时间信息 -->
        <div class="m_time">
                <span>{{nowtime}} / </span>
                <span>{{allTime}}</span>
        </div>
        <!-- 按钮 -->
        <div class="m_btn">
            <a href="#" class="m_prev" @click="playLastSong()"></a>
            <a href="#" class="m_play" @click="changeState()" v-show="this.$parent.isShow"></a>
            <a href="#" class="m_pause" @click="changeState()" v-show="!this.$parent.isShow"></a>
            <a href="#" class="m_next" @click="playNextSong()"></a>
        </div>
        <!-- 折叠功能 -->
        <div class="m_close" @click="changeCloseState()">
            <a href=""></a>
        </div>

    </div>
</template>

<script>
export default {
    name: 'MusicPlayer',
    data() {
        return {
            songName: '',
            value:0.0,
            

        }
    },
    methods: {
        changeState() {

            this.$emit("play")
        },
        changeCloseState() {
            this.$emit("hello");
        },
        playNextSong() {
            this.$emit("nextSongs");
            this.songName = this.$parent.songNames[this.$parent.index].name
        },
        playLastSong() {
            this.$emit("lastSongs");
            this.songName = this.$parent.songNames[this.$parent.index].name
        },
        changeSlideTime()
        {
             const timer = setInterval(()=>{
               this.value = this.$parent.persent;
               
            },30)
        },
        updateSlideTime()
        {
            this.$emit("changeSongsTime",this.value);
        },
        formatTooltip()
        {
            return Math.trunc(this.$parent.currentTime/60)+":"+((Math.trunc(this.$parent.currentTime%60)<10)?("0"+Math.trunc(this.$parent.currentTime%60)):Math.trunc(this.$parent.currentTime%60));
        }
    },
    watch:
    {
       

    },
    computed:{
        nowtime()
        {
            return ((Math.trunc(this.$parent.currentTime/60)<10)?("0"+Math.trunc(this.$parent.currentTime/60)):(Math.trunc(this.$parent.currentTime/60)))+":"+((Math.trunc(this.$parent.currentTime%60)<10)?("0"+Math.trunc(this.$parent.currentTime%60)):(Math.trunc(this.$parent.currentTime%60)));
                    },
        allTime()
        {
            return ((Math.trunc(this.$parent.duration/60)<10)?("0"+Math.trunc(this.$parent.duration/60)):(Math.trunc(this.$parent.duration/60)))+":"+((Math.trunc(this.$parent.duration%60)<10)?("0"+Math.trunc(this.$parent.duration%60)):(Math.trunc(this.$parent.duration%60)));
        }
    } 
    ,mounted() {
        this.songName = this.$parent.songNames[this.$parent.index].name;
        this.changeSlideTime();

    }

}
</script>

<style scoped>
/* 关于播放器的样式 */
.music {
    width: 100%;
    height: 120px;
    background: black;
    /* 相对浏览器定位 */
    position: fixed;
    left: 0px;
    bottom: 0px;
    /* bottom: 100px; */
    /* border-bottom: 50px; */
    /* 透明度 */
    opacity: 0.8;
    /* 阴影值 */
    box-shadow: 10px 15px 15px 1px black
}

.music .m_hold {
    float: left;
    width: 90px;
    height: 90px;
}

/* 调整音乐盒图片 */
.music .m_img {
    margin-top: 15px;
    margin-left: 10px;
    margin-right: 10px;
    /* 左浮动 */
    float: left;
    width: 90px;
    height: 90px;
    border-radius: 50%;
    overflow: hidden;

}

/* 修改文字 */
.music .m_text {
    /* 左浮动 */
    float: left;
    color: white;
    font-size: 20px;
    /* 字体加粗 */
    font-weight: bold;
    margin-top: 25px;
    margin-left: 20px;
    margin-bottom: 10px;
    width: 25%;

}

/* 使得所有a标签一起移动 */
.music .m_btn {
    float: left;
    position: absolute;
    /* 绝对定位：防止歌曲名称过长，挤出div */
    left: 48%;
}

/* 修改a标签 */
.music .m_btn a {
    width: 32px;
    height: 32px;
    float: left;
    margin-top: 50px;
    margin-left: 20px;
    background: url(@/assets/player_bg.png);

}

.music .m_btn .m_prev {
    background-position: -69px 0px;
}

.music .m_btn .m_next {
    background-position: -150px 0px;
}

.music .m_btn .m_play {
    background-position: -107px -5px;
}

.music .m_btn .m_prev:hover {
    background-position: -69px -32px;
}

.music .m_btn .m_next:hover {
    background-position: -150px -32px;
}

.music .m_btn .m_play:hover {
    background-position: -107px -47px;
}

.music .m_btn .m_pause {
    background-position: -292px -94px;
}

.music .m_btn .m_pause:hover {
    background-position: -334px -94px;
}

/* 还有一个悬停 没写 */
/* 设置最右边的关闭样式 */
.music .m_close {
    float: right;
    background: white;
    cursor: pointer;
    width: 23px;
    height: 100px;
    margin-top: 10px;
    background: url(@/assets/player_bg.png);

}
.m_time
{
    width: 100px;
    height: 20px;
    margin-top: 64px;
    float:left;
    margin-left: 10px;
    font:bold
}

/* 设置最右边的关闭样式 */
.music_hide {
    float: left;
    background: white;
    cursor: pointer;
    width: 23px;
    height: 100px;
    margin-top: 2px;
}

.go {
    animation: bounce-in 2s linear infinite;
}

.come {
    animation: none;
}

@keyframes bounce-in {
    from {
        transform: rotate(0deg);
    }

    to {
        transform: rotate(360deg);
    }
}

.open-enter-active {
    animation: slide-in linear 0.5s;
}

.open-leave-active {
    animation: slide-in reverse linear 0.5s;
}

@keyframes slide-in {
    from {
        transform: translateX(-100%);
    }

    to {
        transform: translateX(0%);
    }
}
</style>

HidePlayer.vue

<template>
    <div class="music_hide" @click="changeCloseState()"><a href="#" class="m_open"></a></div>
</template>

<script>
export default {
    name:'HidePlayer',
    methods:{
        changeCloseState()
        {
            this.$emit("hello");
        }
    }
}
</script>

<style scoped>
.music_hide {
    float: left;
    background: url(@/assets/player_bg.png);
    cursor: pointer;
    width: 23px;
    height: 100px;
    margin-top: 10px;
    bottom: 0px;
    /* bottom: 100px; */
    position: fixed;
    background-position-x: -45px;
}
</style>

总结

真可谓是基础不牢，地动山摇，由于CSS，JS学的很浅，现在很多的布局搞不明白，布局效果只有一点点的尝试，导致自己的开发进度变得特别特别缓慢，再次提醒各位C友，一定一定要注重基础的深入学习。勉之哉！！