js 触摸播放音乐

            var f = function(){
                document.body.removeEventListener('touchstart', f);
                
                var xhr = new XMLHttpRequest();
                xhr.open('GET', '/assets/audio/bjmusic.mp3', true);
                xhr.responseType = 'arraybuffer';
                xhr.onload = function(e) {
                    var context = new window.AudioContext();
                    context.decodeAudioData(this.response, function(buffer) {
                        var source = null;
                        source = context.createBufferSource();
                        source.buffer = buffer;
                        source.loop = true;
                        source.connect(context.destination);
                        source.start(0);
                    }, function(e) {
                        console.log('Error decoding file', e);
                    });
                };
                xhr.send();
            }
            document.body.addEventListener('touchstart', f);