未设置canvas.height时，将音频绘制为画布上的声音条不会覆盖上一幅绘制

<canvas id="audioCanvas"></canvas>

const canvas = document.getElementById('audioCanvas');
const ctx = canvas.getContext('2d');

const audioContext = new AudioContext();
const audioElement = document.getElementById('audioElement'); // 获取音频元素
const audioSource = audioContext.createMediaElementSource(audioElement);
const analyser = audioContext.createAnalyser();
audioSource.connect(analyser);
analyser.connect(audioContext.destination);
const bufferLength = analyser.frequencyBinCount;
const dataArray = new Uint8Array(bufferLength);

function draw() {
  requestAnimationFrame(draw);
  
  analyser.getByteFrequencyData(dataArray);
  
  ctx.clearRect(0, 0, canvas.width, canvas.height);
  
  const barWidth = (canvas.width / bufferLength) * 2.5;
  let barHeight;
  let x = 0;
  
  for(let i = 0; i < bufferLength; i++) {
    barHeight = dataArray[i];
    
    ctx.fillStyle = 'rgb(' + (barHeight+100) + ',50,50)';
    ctx.fillRect(x, canvas.height - barHeight/2, barWidth, barHeight/2);
    
    x += barWidth + 1;
  }
}

draw();