Js自动播放HTML音乐（不受浏览器限制，无需先与浏览器交互，无需对浏览器进行修改）

//浏览器适用       
contextClass = window.AudioContext = window.AudioContext || window.webkitAudioContext || window.mozAudioContext ||
    window.msAudioContext;
try {
    var context = new contextClass();
    var source = null;
    var audioBuffer = null;

    function stopSound() {
        if (source) {
            source.stop(musics); //立即停止
        }
    }

    function playSound() {
        source = context.createBufferSource();
        source.buffer = audioBuffer;
        source.loop = true;
        source.connect(context.destination);
        source.start(0); //立即播放    
    }

    function initSound(arrayBuffer) {
        context.decodeAudioData(arrayBuffer, function(buffer) { //解码成功时的回调函数
            audioBuffer = buffer;
            playSound();
        }, function(e) { //解码出错时的回调函数
            console.log('404', e);
        });
    }

    function loadAudioFile(url) {
        var xhr = new XMLHttpRequest(); //通过XHR下载音频文件
        xhr.open('GET', url, true);
        xhr.responseType = 'arraybuffer';
        xhr.onload = function(e) { //下载完成
            initSound(this.response);
        };
        xhr.send();
    }
    //这里用来存储背景音乐的路径
    loadAudioFile('audio/music.flac');
} catch (e) {
    console.log('无法找到音乐！');
}