javascript - 使用 for 循环连续播放音频文件

Question

我有这个 HTML 代码:

<div id="1">Paragraph 1</div>
<div id="2">Paragraph 2</div>
<div id="3">Paragraph 3</div>
<div id="4">Paragraph 4</div>
<div id="5">Paragraph 5</div>

<span id="play">play</span>

我想要做的是，当我点击“播放”时，第 1 段的音频就会播放，在播放时，突出显示该 div，并在后台加载下一段音频，这样音频就不会停止完全加载，并且可以无缝过渡到下一个。现在，当第一段的音频播放完毕时，取消突出显示该 div，然后播放下一段的音频并突出显示它，然后重复该过程，直到循环完成。

我认为通过获取音频文件持续时间并在 for 循环中播放所有音频可以很容易地做到这一点。但这不起作用:

$('#play').on("click",function(){

    var total_paragraphs = 7;

    function playAudio() {

        for (var i = 1; i <= total_paragraphs; i++) {

            var audio = new Audio("paragraphs/"+i+".mp3");

            var sec, ms;

            audio.addEventListener("loadedmetadata", function(_event) {
                seconds = audio.duration.toFixed(2),
                milliseconds = audio.duration.toFixed(2)*1000;
            });

            $("#"+i).css("background-color", "red");

            audio.play();

            audio.onended = function() {
                $("#"+i).css("background-color", "white");
            };

        }

    }

    playAudio();

});

当我点击播放时，所有音频都会同时播放。似乎所有循环都是同时执行的。我想获取音频文件持续时间来延迟循环，但这也不起作用。

我确信有更简单的方法可以做我想做的事。任何帮助，将不胜感激。

Answer 1

怎么样:

html

<div class="paragraph">Paragraph 1</div>
<div class="paragraph">Paragraph 2</div>
<div class="paragraph">Paragraph 3</div>
<div class="paragraph">Paragraph 4</div>
<div class="paragraph">Paragraph 5</div>

<span id="play">play</span>

jquery

_play = (totalParagraphs, currentParagraph) =>
{
    const paragraph = $(`.paragraph:nth-child(${currentParagraph})`)

    if (currentParagraph <= totalParagraphs)
    {
        paragraph.css('background', 'coral');
        const audio = new Audio(`paragraphs/${currentParagraph}.mp3`)
        audio.play()
        audio.onended = () => {
            paragraph.css('background', 'white')
            _play(totalParagraphs, currentParagraph + 1)
        }
    }
}

$('#play').on('click', () => {

    let totalParagraphs  = $('.paragraph').length,
        currentParagraph = 1

    _play(totalParagraphs, currentParagraph)

})