js获取html5 audio 音频时长方法

var myVid = $('#' + showImgId)[0];
                                if (myVid != null) {
                                    var duration;
                                    myVid.load();
                                    myVid.oncanplay = function () {
                                        console.log("myVid.duration", myVid.duration);
                                    }
                                }

var time = _audio.duration;
        //分钟
    var minute = time / 60;
    var minutes = parseInt(minute);
    if (minutes < 10) {
        minutes = "0" + minutes;
    }
    //秒
    var second = time % 60;
    var seconds = Math.round(second);
    if (seconds < 10) {
        seconds = "0" + seconds;
    }