HTML5自动播放背景音乐

<audio src="./audio/bgmusic.mp3" preload="meta" loop autoplay id="bgmusic"></audio>

var bgmusic = document.getElementById('bgmusic');
bgmusic.addEventListener('canplay', function(){
this.play();
}, false);
window.addEventListener('load', function(){
window.addEventListener('touchstart', once, false);
}, false);
function once(){
bgmusic.play();
window.removeEventListener('touchstart', once, false);
}