Question

出于性能考虑，我正在尝试推迟在网站上加载YouTube CSS和JavaScript。但是，使用Google的Page Speed Insights对我的页面进行扫描表明未延迟YouTube CSS文件https://www.youtube.com/yts/cssbin/www-player-sprite-mode-vflixBY8E.css。我还测试了删除JavaScript，以确保其他资源未请求CSS文件，但事实并非如此。

这是我正在使用的代码：

在我的main.js文件中（已延迟）

function init() {
    var vidDefer = document.getElementsByClassName('youtube');
    for (var i=0; i<vidDefer.length; i++) {
        if(vidDefer[i].getAttribute('data-src')) {
            vidDefer[i].setAttribute('src',vidDefer[i].getAttribute('data-src'));
        } 
    } 
}
window.onload = init;

然后，iframe如下所示：

<iframe class="youtube" id="home-youtube" src="" data-src="https://www.youtube.com/embed/QHfgMrpMOm4" frameborder="0" allowfullscreen></iframe>

预先感谢

Answer 1

您始终可以尝试使用Youtube的javascript API和

https://developers.google.com/youtube/iframe_api_reference

<!DOCTYPE html>
<html>
  <body>
    <!-- 1. The <iframe> (and video player) will replace this <div> tag. -->
    <div id="player"></div>

    <script>
      // 2. This code loads the IFrame Player API code asynchronously.
      var tag = document.createElement('script');

      tag.src = "https://www.youtube.com/iframe_api";
      var firstScriptTag = document.getElementsByTagName('script')[0];
      firstScriptTag.parentNode.insertBefore(tag, firstScriptTag);

      // 3. This function creates an <iframe> (and YouTube player)
      //    after the API code downloads.
      var player;
      function onYouTubeIframeAPIReady() {
        player = new YT.Player('player', {
          height: '390',
          width: '640',
          videoId: 'M7lc1UVf-VE',
          events: {
            'onReady': onPlayerReady,
            'onStateChange': onPlayerStateChange
          }
        });
      }

      // 4. The API will call this function when the video player is ready.
      function onPlayerReady(event) {
        event.target.playVideo();
      }

      // 5. The API calls this function when the player's state changes.
      //    The function indicates that when playing a video (state=1),
      //    the player should play for six seconds and then stop.
      var done = false;
      function onPlayerStateChange(event) {
        if (event.data == YT.PlayerState.PLAYING && !done) {
          setTimeout(stopVideo, 6000);
          done = true;
        }
      }
      function stopVideo() {
        player.stopVideo();
      }
    </script>
  </body>
</html>

无法使用JavaScript延迟Youtube CSS

1 个答案: