JAVASCRIPT 音频应用程序：按钮不会根据设备而变化

Question

这是一个 html 带有简单控件的嵌入式音频播放器。我把它作为我网站的插件。由于移动浏览器不支持自动播放。 play/pause 按钮根据设备变化即：播放按钮显示在移动设备上，暂停按钮显示在电脑上

播放器的移动端运行完美。但是它的 pc 端从播放按钮开始，即使音频正在后台播放。 IE。否则条件不工作

如果错误不清楚，请在此处复制粘贴代码并查看：www.htmledit.squarefree.com

    <head>


        <script>
            var playing = true;

            if (/Android|iPhone|iPad|Mobile|Mobi|iPod|BlackBerry|BB|PlayBook|IEMobile|Windows Phone|Kindle|Silk|Opera Mini/i.test(navigator.userAgent)) {
                playing = false;
            }
     <!-- THIS ELSE DOES NOT WORK . IT IS SUPPOSED TO CHANGE THE ICON TO PAUSE FROM PRE DEFINED PLAY  ICON-->
            else{
                document.getElementById('sound_icon').src = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAADAAAAAwCAYAAABXAvmHAAAAuUlEQVRoQ+2YwQ2AIAxFYRwncS3WchLH0YN6IWp/QhtCeJ5rgfd/W0JOg3958P0nDtBbQRRAgUYCWKgRYPPv8yiwlO1QcO1l/YXilefZi6yA18JeeTjAl52w0E3GAoGFsJDRk7FQDcirf3vloYgpYor4IsBlrnaC1b/pQhUxLISFPtqpVUtMYiYxk5hJ/O4Bq3swiaedxMq7aI8Y+S7UY3PKmhxAoRQZgwKRdJXcKKBQioxBgUi6Su4TGV3gMZ8LoyUAAAAASUVORK5CYII=";
            }



            function EvalSound(soundobj) {
                var thissound = document.getElementById(soundobj);

                if (!playing) {
                    thissound.play();
                    playing = true;
                    document.getElementById('sound_icon').src = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAADAAAAAwCAYAAABXAvmHAAAAuUlEQVRoQ+2YwQ2AIAxFYRwncS3WchLH0YN6IWp/QhtCeJ5rgfd/W0JOg3958P0nDtBbQRRAgUYCWKgRYPPv8yiwlO1QcO1l/YXilefZi6yA18JeeTjAl52w0E3GAoGFsJDRk7FQDcirf3vloYgpYor4IsBlrnaC1b/pQhUxLISFPtqpVUtMYiYxk5hJ/O4Bq3swiaedxMq7aI8Y+S7UY3PKmhxAoRQZgwKRdJXcKKBQioxBgUi6Su4TGV3gMZ8LoyUAAAAASUVORK5CYII=";
                } else if (playing) {
                    thissound.pause();
                    playing = false;
                    document.getElementById('sound_icon').src = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAADAAAAAwCAYAAABXAvmHAAABdElEQVRoQ+2YuxWCQBBFl0Rb0TJM9NiFdoAVOHSAHWAZZtoFoXagGZHroOghMHA+++G4JCT7mTvv8VjIzMCvbOD1mwQQWsGkQFJA2IFkIWEDxdP/V4EJHI7G3Fc1LM/iNgoWYCswhYNt97WZgcaOdmeYXQV1sKeKAbqdrwiS19vFnl0Jc6IWwHN7ayzayhZoK7z7uVQB3iUjSNWY8caHrZwA9GxVoq0Kl1q4BHjbClPKrl3ZyjlAz1bt89GCqMauN4APiHLsegfQjt1QAGqxGxRAI3ajAJDEbkwArNiNDgCj9oJv8vaU+9NxJBoAPNreUIKyhgVQ3txRAGDx+8aMcs7ZKSgAFn7CjyL41S7flAkC8LJLltcwryh2iQIAiy/QLiXHLkEBOruof0N7sBAtFqmWcgbAjcUoACSxGBRAIxaDAGjGoncA7Vj0BjD4X4vUTrkaz45RVwVR100A1I5pj08KaHeUul5SgNox7fFJAe2OUtd7AO2p3zFrWh4hAAAAAElFTkSuQmCC";
                }
            }

        </script>
    </head>



    <body>

        <a href="javascript:null()" onClick="EvalSound('sound1'); return false; ">

<!-- PRE DEFINED PLAY ICON IS BELOW -->

            <img src="data:image/png;base64,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" id="sound_icon" name="Sound" width="" height="" title="Background Music Controls" class="" /></a>


        <audio id="sound1" style="display: none; width: 0px; height: 0px;" src="https://audio.clyp.it/3fnnuaiw.mp3?Expires=1488659248&Signature=01NkRScwYO4XaJO46JuNzPRR6cYQfcL5~rJzAu-gIoNoXkiMVZwazwT--amuqYvreLCSRFnFAFUvwR3v9Xaq1iB4~OmKSWqtF9mSm-CUB2Moqtie8wpGIRxTAkDHnfhN0sy45sINjwFP2xyVumld78USPuCBfNU3kgux69YG-yA_&Key-Pair-Id=APKAJ4AMQB3XYIRCZ5PA" controls preload="auto" autobuffer autoplay>
    </body>

Answer 1

加载页面时，headers 处的脚本部分在 DOM 处创建的元素之前运行。请参阅 this other answer 以更好地了解其工作原理。

要使其正常运行，您可以在末尾加载脚本：

<body>

  <a href="javascript:null()" onClick="EvalSound('sound1'); return false; ">

<!-- PRE DEFINED PLAY ICON IS BELOW -->

      <img src="data:image/png;base64,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" id="sound_icon" name="Sound" width="" height="" title="Background Music Controls" class="" /></a>


  <audio id="sound1" style="display: none; width: 0px; height: 0px;" src="https://audio.clyp.it/3fnnuaiw.mp3?Expires=1488659248&Signature=01NkRScwYO4XaJO46JuNzPRR6cYQfcL5~rJzAu-gIoNoXkiMVZwazwT--amuqYvreLCSRFnFAFUvwR3v9Xaq1iB4~OmKSWqtF9mSm-CUB2Moqtie8wpGIRxTAkDHnfhN0sy45sINjwFP2xyVumld78USPuCBfNU3kgux69YG-yA_&Key-Pair-Id=APKAJ4AMQB3XYIRCZ5PA" controls preload="auto" autobuffer autoplay>

  <script>
      var playing = true;
      var flag = false;
      if (/Android|iPhone|iPad|Mobile|Mobi|iPod|BlackBerry|BB|PlayBook|IEMobile|Windows Phone|Kindle|Silk|Opera Mini/i.test(navigator.userAgent)) {
          playing = false;
      } else{
          document.getElementById('sound_icon').src = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAADAAAAAwCAYAAABXAvmHAAAAuUlEQVRoQ+2YwQ2AIAxFYRwncS3WchLH0YN6IWp/QhtCeJ5rgfd/W0JOg3958P0nDtBbQRRAgUYCWKgRYPPv8yiwlO1QcO1l/YXilefZi6yA18JeeTjAl52w0E3GAoGFsJDRk7FQDcirf3vloYgpYor4IsBlrnaC1b/pQhUxLISFPtqpVUtMYiYxk5hJ/O4Bq3swiaedxMq7aI8Y+S7UY3PKmhxAoRQZgwKRdJXcKKBQioxBgUi6Su4TGV3gMZ8LoyUAAAAASUVORK5CYII=";
      }



      function EvalSound(soundobj) {
          var thissound = document.getElementById(soundobj);

          if (!playing) {
              thissound.play();
              playing = true;
              document.getElementById('sound_icon').src = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAADAAAAAwCAYAAABXAvmHAAAAuUlEQVRoQ+2YwQ2AIAxFYRwncS3WchLH0YN6IWp/QhtCeJ5rgfd/W0JOg3958P0nDtBbQRRAgUYCWKgRYPPv8yiwlO1QcO1l/YXilefZi6yA18JeeTjAl52w0E3GAoGFsJDRk7FQDcirf3vloYgpYor4IsBlrnaC1b/pQhUxLISFPtqpVUtMYiYxk5hJ/O4Bq3swiaedxMq7aI8Y+S7UY3PKmhxAoRQZgwKRdJXcKKBQioxBgUi6Su4TGV3gMZ8LoyUAAAAASUVORK5CYII=";
          } else if (playing) {
              thissound.pause();
              playing = false;
              document.getElementById('sound_icon').src = "data:image/png;base64,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";
          }
      }

  </script>
</body>

或在window加载后加载window.onload

<head>
<script>
  var playing = true;
  var flag = false;

  window.onload = function () {
    if (/Android|iPhone|iPad|Mobile|Mobi|iPod|BlackBerry|BB|PlayBook|IEMobile|Windows Phone|Kindle|Silk|Opera Mini/i.test(navigator.userAgent)) {
      playing = false;
    } else {
      document.getElementById('sound_icon').src = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAADAAAAAwCAYAAABXAvmHAAAAuUlEQVRoQ+2YwQ2AIAxFYRwncS3WchLH0YN6IWp/QhtCeJ5rgfd/W0JOg3958P0nDtBbQRRAgUYCWKgRYPPv8yiwlO1QcO1l/YXilefZi6yA18JeeTjAl52w0E3GAoGFsJDRk7FQDcirf3vloYgpYor4IsBlrnaC1b/pQhUxLISFPtqpVUtMYiYxk5hJ/O4Bq3swiaedxMq7aI8Y+S7UY3PKmhxAoRQZgwKRdJXcKKBQioxBgUi6Su4TGV3gMZ8LoyUAAAAASUVORK5CYII=";
    }
  }



  function EvalSound(soundobj) {
    var thissound = document.getElementById(soundobj);

    if (!playing) {
      thissound.play();
      playing = true;
      document.getElementById('sound_icon').src = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAADAAAAAwCAYAAABXAvmHAAAAuUlEQVRoQ+2YwQ2AIAxFYRwncS3WchLH0YN6IWp/QhtCeJ5rgfd/W0JOg3958P0nDtBbQRRAgUYCWKgRYPPv8yiwlO1QcO1l/YXilefZi6yA18JeeTjAl52w0E3GAoGFsJDRk7FQDcirf3vloYgpYor4IsBlrnaC1b/pQhUxLISFPtqpVUtMYiYxk5hJ/O4Bq3swiaedxMq7aI8Y+S7UY3PKmhxAoRQZgwKRdJXcKKBQioxBgUi6Su4TGV3gMZ8LoyUAAAAASUVORK5CYII=";
    } else if (playing) {
      thissound.pause();
      playing = false;
      document.getElementById('sound_icon').src = "data:image/png;base64,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";
    }
  }

</script>
</head>

<body>

<a href="javascript:null()" onClick="EvalSound('sound1'); return false; ">

<!-- PRE DEFINED PLAY ICON IS BELOW -->

<img src="data:image/png;base64,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" id="sound_icon" name="Sound" width="" height="" title="Background Music Controls" class="" /></a>


<audio id="sound1" style="display: none; width: 0px; height: 0px;" src="https://audio.clyp.it/3fnnuaiw.mp3?Expires=1488659248&Signature=01NkRScwYO4XaJO46JuNzPRR6cYQfcL5~rJzAu-gIoNoXkiMVZwazwT--amuqYvreLCSRFnFAFUvwR3v9Xaq1iB4~OmKSWqtF9mSm-CUB2Moqtie8wpGIRxTAkDHnfhN0sy45sINjwFP2xyVumld78USPuCBfNU3kgux69YG-yA_&Key-Pair-Id=APKAJ4AMQB3XYIRCZ5PA" controls preload="auto" autobuffer autoplay>

</body>

JAVASCRIPT 音频应用程序：按钮不会根据设备而变化

JAVASCRIPT audio application : Button does not change according to device

html

javascript

audio

jquery

web-audio-api