為什么這個計算屬性的更新在我的Vue3應用程式中失敗？-有解無憂

我正在使用 Vue 3 和 Napster API 開發音頻播放器。

專案詳情

我在基于 CSS 關鍵幀的影片和isSpinning計算屬性的幫助下制作了乙烯基旋轉。

一旦到達當前曲目的末尾，我希望乙烯基停止旋轉，這就是為什么isSpinning有這個“公式”：

isSpinning() {
  return this.isPlaying && !this.player.ended;
}

const musicApp = {
  data() {
    return {
      player: new Audio(),
      trackCount: 0,
      tracks: [],
      muted: false,
      isPlaying: false
    };
  },
  methods: {
    async getTracks() {
      try {
        const response = await axios
          .get(
            "https://api.napster.com/v2.1/tracks/top?apikey=ZTk2YjY4MjMtMDAzYy00MTg4LWE2MjYtZDIzNjJmMmM0YTdm"
          )
          .catch((error) => {
            console.log(error);
          });
        this.tracks = response;
        this.tracks = response.data.tracks;
      } catch (error) {
        console.log(error);
      }
    },
    nextTrack() {
      if (this.trackCount < this.tracks.length - 1) {
        this.trackCount  ;
        this.setPlayerSource();
        this.playPause();
      }
    },
    prevTrack() {
      if (this.trackCount >= 1) {
        this.trackCount--;
        this.setPlayerSource();
        this.playPause();
      }
    },
    setPlayerSource() {
      this.player.src = this.tracks[this.trackCount].previewURL;
    },
    playPause() {
      if (this.player.paused) {
        this.isPlaying = true;
        this.player.play();
      } else {
        this.isPlaying = false;
        this.player.pause();
      }
    },
    toggleMute() {
      this.player.muted = !this.player.muted;
      this.muted = this.player.muted;
    }
  },
  async created() {
    await this.getTracks();
    this.setPlayerSource();
  },
  computed: {
    isSpinning() {
      return this.isPlaying && !this.player.ended;
    }
  }
};

Vue.createApp(musicApp).mount("#audioPlayer");

html,
body {
  margin: 0;
  padding: 0;
  font-size: 16px;
}

body * {
  box-sizing: border-box;
  font-family: "Montserrat", sans-serif;
}

@-webkit-keyframes spin {
  0% {
    -webkit-transform: rotate(0deg);
  }
  100% {
    -webkit-transform: rotate(360deg);
  }
}

@keyframes spin {
  0% {
    transform: rotate(0deg);
  }
  100% {
    transform: rotate(360deg);
  }
}

.player-container {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  background-color: #2998ff;
  background-image: linear-gradient(62deg, #2998ff 0%, #5966eb 100%);
}

#audioPlayer {
  width: 300px;
  height: 300px;
  border-radius: 8px;
  position: relative;
  overflow: hidden;
  background-color: #00ca81;
  background-image: linear-gradient(160deg, #00ca81 0%, #ffffff 100%);
  box-shadow: 0 0.125rem 0.25rem rgba(0, 0, 0, 0.075);
  display: flex;
  flex-direction: column;
  align-items: center;
}

.volume {
  color: #ff0057;
  opacity: 0.9;
  display: inline-block;
  width: 20px;
  font-size: 20px;
  position: absolute;
  top: 5px;
  right: 6px;
  cursor: pointer;
}

.album {
  width: 100%;
  flex: 1;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
}

.album-items {
  padding: 0 10px;
  text-align: center;
}

.cover {
  width: 150px;
  height: 150px;
  margin: auto;
  box-shadow: 0px 5px 12px 0px rgba(0, 0, 0, 0.17);
  border-radius: 50%;
  background: url("https://w7.pngwing.com/pngs/710/955/png-transparent-vinyl-record-artwork-phonograph-record-compact-disc-lp-record-disc-jockey-symbol-miscellaneous-classical-music-sound.png") center top transparent;
  background-size: cover;
}

.cover.spinning {
  webkit-animation: spin 6s linear infinite;
  /* Safari */
  animation: spin 6s linear infinite;
}

.info {
  width: 100%;
  padding-top: 5px;
  color: #000;
  opacity: 0.85;
}

.info h1 {
  font-size: 11px;
  margin: 5px 0 0 0;
}

.info h2 {
  font-size: 10px;
  margin: 3px 0 0 0;
}

.to-bottom {
  width: 100%;
  margin-top: auto;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
}

.track {
  background-color: #ff0057;
  opacity: 0.9;
  height: 3px;
  width: 100%;
}

.controls {
  width: 150px;
  display: flex;
  height: 60px;
  justify-content: space-between;
  align-items: center;
}

.controls .navigate {
  display: flex;
  box-shadow: 1px 2px 7px 2px rgba(0, 0, 0, 0.09);
  width: 33px;
  height: 33px;
  line-height: 1;
  color: #ff0057;
  cursor: pointer;
  background: #fff;
  opacity: 0.9;
  border-radius: 50%;
  text-align: center;
  justify-content: center;
  align-items: center;
}

.controls .navigate.disabled {
  pointer-events: none;
  color: #606060;
  background-color: #f7f7f7;
}

.controls .navigate.navigate-play {
  width: 38px;
  height: 38px;
}

.navigate-play .fa-play {
  margin-left: 3px;
}

<link href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css" rel="stylesheet" />
<script src="https://unpkg.com/[email protected]/dist/axios.min.js"></script>
<script src="https://unpkg.com/vue@next"></script>
<link href="https://fonts.googleapis.com/css2?family=Montserrat:wght@300;500&display=swap" rel="stylesheet">

<div class="player-container">
  <div id="audioPlayer">
    <span class="volume" @click="toggleMute">
      <i v-show="!muted" class="fa fa-volume-up"></i>
      <i v-show="muted" class="fa fa-volume-off"></i>
    </span>
    <div class="album">
      <div class="album-items">
        <div class="cover" :class="{'spinning' : isSpinning}"></div>
        <div class="info">
          <h1>{{tracks[trackCount].name}}</h1>
          <h2>{{tracks[trackCount].artistName}}</h2>
        </div>
      </div>
    </div>

    <div class="to-bottom">
      <div class="track"></div>
      <div class="controls">
        <div class="navigate navigate-prev" :class="{'disabled' : trackCount == 0}" @click="prevTrack">
          <i class="fa fa-step-backward"></i>
        </div>
        <div class="navigate navigate-play" @click="playPause">
          <i v-show="!isPlaying" class="fa fa-play"></i>
          <i v-show="isPlaying" class="fa fa-pause"></i>
        </div>
        <div class="navigate navigate-next" :class="{'disabled' : trackCount == tracks.length - 1}" @click="nextTrack">
          <i class="fa fa-step-forward"></i>
        </div>
      </div>
    </div>
  </div>
</div>

問題

但是，令我驚訝的是，該應用程式并不知道的值this.player.ended已更改（或應該更改）這一事實。

我究竟做錯了什么？

uj5u.com熱心網友回復：

一個Audio物件將不會以相同的方式作為正常的JavaScript在Vue的物件，作為內部，當Vue的用途抽象掉的狀態變化的觀察不會被維持Audio物件改變狀態。也就是說，讓 Vue 檢測到Audio物件從切換ended === false到的東西是ended === true行不通的，阻止 Vue 知道組件需要更新。

如果您希望觀察ended狀態的變化，那么您需要向created鉤子中的物件添加一個自定義事件偵聽器以切換旋轉狀態并簡單地洗掉ended檢查：

const musicApp = {
  data() {
    return {
      player: new Audio(),
      trackCount: 0,
      tracks: [],
      muted: false,
      isPlaying: false
    };
  },
  methods: {
    async getTracks() {
      try {
        const response = await axios
          .get(
            "https://api.napster.com/v2.1/tracks/top?apikey=ZTk2YjY4MjMtMDAzYy00MTg4LWE2MjYtZDIzNjJmMmM0YTdm"
          )
          .catch((error) => {
            console.log(error);
          });
        this.tracks = response;
        this.tracks = response.data.tracks;
      } catch (error) {
        console.log(error);
      }
    },
    nextTrack() {
      if (this.trackCount < this.tracks.length - 1) {
        this.trackCount  ;
        this.setPlayerSource();
        this.playPause();
      }
    },
    prevTrack() {
      if (this.trackCount >= 1) {
        this.trackCount--;
        this.setPlayerSource();
        this.playPause();
      }
    },
    setPlayerSource() {
      this.player.src = this.tracks[this.trackCount].previewURL;
    },
    playPause() {
      if (this.player.paused) {
        this.isPlaying = true;
        this.player.play();
      } else {
        this.isPlaying = false;
        this.player.pause();
      }
    },
    toggleMute() {
      this.player.muted = !this.player.muted;
      this.muted = this.player.muted;
    }
  },
  async created() {
    await this.getTracks();
    this.setPlayerSource();
    this.player.addEventListener('ended', () => {
      this.isPlaying = false;
    });
  },
  computed: {
    isSpinning() {
      return this.isPlaying;
    }
  }
};

Vue.createApp(musicApp).mount("#audioPlayer");

html,
body {
  margin: 0;
  padding: 0;
  font-size: 16px;
}

body * {
  box-sizing: border-box;
  font-family: "Montserrat", sans-serif;
}

@-webkit-keyframes spin {
  0% {
    -webkit-transform: rotate(0deg);
  }
  100% {
    -webkit-transform: rotate(360deg);
  }
}

@keyframes spin {
  0% {
    transform: rotate(0deg);
  }
  100% {
    transform: rotate(360deg);
  }
}

.player-container {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  background-color: #2998ff;
  background-image: linear-gradient(62deg, #2998ff 0%, #5966eb 100%);
}

#audioPlayer {
  width: 300px;
  height: 300px;
  border-radius: 8px;
  position: relative;
  overflow: hidden;
  background-color: #00ca81;
  background-image: linear-gradient(160deg, #00ca81 0%, #ffffff 100%);
  box-shadow: 0 0.125rem 0.25rem rgba(0, 0, 0, 0.075);
  display: flex;
  flex-direction: column;
  align-items: center;
}

.volume {
  color: #ff0057;
  opacity: 0.9;
  display: inline-block;
  width: 20px;
  font-size: 20px;
  position: absolute;
  top: 5px;
  right: 6px;
  cursor: pointer;
}

.album {
  width: 100%;
  flex: 1;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
}

.album-items {
  padding: 0 10px;
  text-align: center;
}

.cover {
  width: 150px;
  height: 150px;
  margin: auto;
  box-shadow: 0px 5px 12px 0px rgba(0, 0, 0, 0.17);
  border-radius: 50%;
  background: url("https://w7.pngwing.com/pngs/710/955/png-transparent-vinyl-record-artwork-phonograph-record-compact-disc-lp-record-disc-jockey-symbol-miscellaneous-classical-music-sound.png") center top transparent;
  background-size: cover;
}

.cover.spinning {
  webkit-animation: spin 6s linear infinite;
  /* Safari */
  animation: spin 6s linear infinite;
}

.info {
  width: 100%;
  padding-top: 5px;
  color: #000;
  opacity: 0.85;
}

.info h1 {
  font-size: 11px;
  margin: 5px 0 0 0;
}

.info h2 {
  font-size: 10px;
  margin: 3px 0 0 0;
}

.to-bottom {
  width: 100%;
  margin-top: auto;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
}

.track {
  background-color: #ff0057;
  opacity: 0.9;
  height: 3px;
  width: 100%;
}

.controls {
  width: 150px;
  display: flex;
  height: 60px;
  justify-content: space-between;
  align-items: center;
}

.controls .navigate {
  display: flex;
  box-shadow: 1px 2px 7px 2px rgba(0, 0, 0, 0.09);
  width: 33px;
  height: 33px;
  line-height: 1;
  color: #ff0057;
  cursor: pointer;
  background: #fff;
  opacity: 0.9;
  border-radius: 50%;
  text-align: center;
  justify-content: center;
  align-items: center;
}

.controls .navigate.disabled {
  pointer-events: none;
  color: #606060;
  background-color: #f7f7f7;
}

.controls .navigate.navigate-play {
  width: 38px;
  height: 38px;
}

.navigate-play .fa-play {
  margin-left: 3px;
}

<link href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css" rel="stylesheet" />
<script src="https://unpkg.com/[email protected]/dist/axios.min.js"></script>
<script src="https://unpkg.com/vue@next"></script>
<link href="https://fonts.googleapis.com/css2?family=Montserrat:wght@300;500&display=swap" rel="stylesheet">

<div class="player-container">
  <div id="audioPlayer">
    <span class="volume" @click="toggleMute">
      <i v-show="!muted" class="fa fa-volume-up"></i>
      <i v-show="muted" class="fa fa-volume-off"></i>
    </span>
    <div class="album">
      <div class="album-items">
        <div class="cover" :class="{'spinning' : isSpinning}"></div>
        <div class="info">
          <h1>{{tracks[trackCount].name}}</h1>
          <h2>{{tracks[trackCount].artistName}}</h2>
        </div>
      </div>
    </div>

    <div class="to-bottom">
      <div class="track"></div>
      <div class="controls">
        <div class="navigate navigate-prev" :class="{'disabled' : trackCount == 0}" @click="prevTrack">
          <i class="fa fa-step-backward"></i>
        </div>
        <div class="navigate navigate-play" @click="playPause">
          <i v-show="!isPlaying" class="fa fa-play"></i>
          <i v-show="isPlaying" class="fa fa-pause"></i>
        </div>
        <div class="navigate navigate-next" :class="{'disabled' : trackCount == tracks.length - 1}" @click="nextTrack">
          <i class="fa fa-step-forward"></i>
        </div>
      </div>
    </div>
  </div>
</div>

uj5u.com熱心網友回復：

嘗試添加ended事件

https://developer.mozilla.org/en-US/docs/Web/API/HTMLAudioElement#events

const audioElement = new Audio('car_horn.wav');
audioElement.addEventListener('ended', () => {
  this.isPlaying = false
})

轉載請註明出處，本文鏈接：https://www.uj5u.com/ruanti/395510.html

標籤：javascript css Vue.js Vuejs3

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