如果放入 dom 就绪功能,YouTube 视频 JavaScript 会停止工作吗?

YouTube video JavaScript stops working if put in dom ready function?

当我完全复制 youtube 演示代码时,它工作正常:

http://jsfiddle.net/czvufy75/1/

<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>

但是一旦我将其放入 dom 就绪函数中,就什么也没有发生。为什么是这样?

http://jsfiddle.net/czvufy75/2/

$(function() {
    // 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();
      }

        $('.trigger').click(function(){
            //this works
            player.pauseVideo()
        });
});

http://jsfiddle.net/czvufy75/4/

您的问题是:函数 onYouTubeIframeAPIReady() {...} 未执行,因为 iframe_api 未在全局范围内找到它,这是一个小修复:)

onYouTubeIframeAPIReady = function onYouTubeIframeAPIReady() {
          console.log(done);
        player = new YT.Player('player', {
          height: '390',
          width: '640',
          videoId: 'M7lc1UVf-VE',
          events: {
            'onReady': onPlayerReady,
            'onStateChange': onPlayerStateChange
          }
        });
      }