在如下路径中新建index.js用于存储全局变量：

index.js代码如下，这里定义了两个变量，playlist和playCurrentIndex，

import { createStore } from 'vuex'

export default createStore({
  state: {
    playlist:[
        {al:{},}
    ],
    playCurrentIndex:0,
  },
  getters: {
  },
  mutations: {
    // 用来修改state中的playlist
    setPlaylist:function (state,value) {
      state.playlist = value
    },
    setPlayIndex:function (state,index) {
      state.playCurrentIndex = index
    }
  },
  actions: {
  },
  modules: {
  }
})

1.修改

 在组件中，用如下代码将api中的数组用于替换index.js中的playlist变量

 关键代码：

this.$store.commit('setPlaylist',this.playlist.tracks);

2.使用

在组件中，用如下代码，调用index.js中的全局变量：

 关键代码：

import {mapState,mapMutations} from 'vuex'

computed:{
            ...mapState(['playlist','playCurrentIndex'])
        },

<img class="songPhoto" :src="playlist[playCurrentIndex].al.picUrl">
<div class="singName">{{playlist[playCurrentIndex].name}}</div>

<audio :src="`https://music.163.com/song/media/outer/url?id=${playlist[playCurrentIndex].id}.mp3`"></audio>

methods:{
    console.log(this.playCurrentIndex)
    // 或
    console.log(this.$store.state.playCurrentIndex)
}