js逐步教实现音乐系统

html部分:

 <div class="keys">
    <div data-key="65" class="key">
      <kbd>A</kbd>
      <span class="sound">clap</span>
    </div>
    <div data-key="83" class="key">
      <kbd>S</kbd>
      <span class="sound">hihat</span>
    </div>
    <div data-key="68" class="key">
      <kbd>D</kbd>
      <span class="sound">kick</span>
    </div>
    <div data-key="70" class="key">
      <kbd>F</kbd>
      <span class="sound">openhat</span>
    </div>
    <div data-key="71" class="key">
      <kbd>G</kbd>
      <span class="sound">boom</span>
    </div>
    <div data-key="72" class="key">
      <kbd>H</kbd>
      <span class="sound">ride</span>
    </div>
    <div data-key="74" class="key">
      <kbd>J</kbd>
      <span class="sound">snare</span>
    </div>
    <div data-key="75" class="key">
      <kbd>K</kbd>
      <span class="sound">tom</span>
    </div>
    <div data-key="76" class="key">
      <kbd>L</kbd>
      <span class="sound">tink</span>
    </div>
  </div>
  <audio data-key="65" src="sounds/clap.wav"></audio>
   <audio data-key="83" src="sounds/hihat.wav"></audio>
  <audio data-key="68" src="sounds/kick.wav"></audio>
  <audio data-key="70" src="sounds/openhat.wav"></audio>
  <audio data-key="71" src="sounds/boom.wav"></audio>
  <audio data-key="72" src="sounds/ride.wav"></audio>
  <audio data-key="74" src="sounds/snare.wav"></audio>
  <audio data-key="75" src="sounds/tom.wav"></audio>
  <audio data-key="76" src="sounds/tink.wav"></audio>

图片展示:

注意一下: div为动画,audio为声音.

css部分:

*{padding: 0px;margin: 0px;list-style: none;font-family: sans-serif;}
    html{
      font-size: 12px;
    }
    .keys
    {
      display: flex;
      min-height: 100vh;
   
      align-items: center;
      justify-content: center;
      flex: 1;
     
     }
    .key
    {
      border: 0.4rem solid black;
      border-radius: .5rem;
      font-size: 1.5rem;
      padding: 1rem .5rem;
      transition: all .07s ease;
      text-align: center;
      color: white;
      width: 10rem;
      background: rgba(0,0,0,0.4);
      text-shadow: 0 0 .5rem black;
    }
    .playing
  {
    transform: scale(1.1);
    border-color: #ffc600;
    box-shadow: 0 0 1rem #FFC600;
  }
  kbd
  {
    display: block;
    font-size: 4rem;
  }
  .sound
  {
    font-size: 1.2rem;
    letter-spacing: .1rem;
    color: #ffc600;
    text-transform: uppercase;
  }

图片描述:

注意一下这里:

我只说最难点：flex:1;代表太大了就缩小到占满整个body的部分(系统合理分配),太小了就扩大到合适到占满整个整个body的地步（系统合理分配）.

js部分:

<script>
    function removeTransition(e) {
      if (e.propertyName !== 'transform') return;
      e.target.classList.remove('playing');
    }

    function playSound(e) {
      const audio = document.querySelector(`audio[data-key="${e.keyCode}"]`);
      const key = document.querySelector(`div[data-key="${e.keyCode}"]`);
      if (!audio) return;

      key.classList.add('playing');
      audio.currentTime=0;
      audio.play();
    }

    const keys = Array.from(document.querySelectorAll('.key'));
    keys.forEach(key => key.addEventListener('transitionend', removeTransition));
    window.addEventListener('keydown', playSound);
  </script>

图片展示:

注意一下: 整块项目的代码逻辑: js核心逻辑: 当窗口察觉到了你按下了有上面图片中的某一个键时,就playing(动画)起来,并且音乐从0开始播放。当playing与play():(声音)也就是动画结束之后,就移除动画. 注意一下: 要用什么得先获取第二；先判断是否有这种东西

if (!audio) return;

第三:说

 `if(e.propertyName!=="transform")return;`

这里还没有发生你说还要做什么？？是吧。