bgm.start(); var bgm = { typedef : [\'ji\',\'niu\',\'yang\',\'niao\'], buffer : {}, context : null, timeout : 3000, start: function(){ this.cacheBuf(); this.run(); }, run: function(){ setTimeout(function(){ if(this.context != null){ this.context.close(); this.context = null; } var _li = Math.floor((Math.random()*this.typedef.length)); this.audioPlay(this.typedef[_li]); this.run(); }, this.timeout); }, audioPlay: function(tp){ var _this = this; var _buff = this.buffer[tp].slice(0, this.buffer[tp].byteLength); this.context = new (window.AudioContext || window.webkitAudioContext)(); this.context.decodeAudioData(_buff, function(buffer){ var source = _this.context.createBufferSource(); source.buffer = buffer; source.connect(_this.context.destination); source.start(0); }); }, cacheBuf: function(){for(i in this.typedef){ _tp = this.typedef[i]; this.getbuf(\'static/audio/\'+ _tp +\'.mp3\', _tp); } }, getbuf: function(url, tp){ var _this = this; var xhr = new XMLHttpRequest(); xhr.open(\'GET\', url, true); xhr.responseType = \'arraybuffer\'; xhr.onreadystatechange = function () { if (xhr.readyState === 4 && xhr.status === 200) { _this.buffer[tp] = xhr.response; } }; xhr.send(); } };