<video data-state="0" width="100%" autoplay="" controls src="http://ovcccrdo8.bkt.clouddn.com/maven_mp4/01%E6%95%B4%E4%BD%93%E8%AF%BE%E7%A8%8B%E4%BB%8B%E7%BB%8D.mp4"></video>
<script>
            document.addEventListener("webkitfullscreenchange", function(e) {

              var state = e.target.getAttribute('data-state');
              if (state == '0'){
//                  alert('全屏操作');
                  e.target.setAttribute('data-state', '1');
                  api.setScreenOrientation({
                    orientation: 'landscape_left'
                });
              } else {
//                  alert('不是全屏操作');
                  e.target.setAttribute('data-state', '0');
                  api.setScreenOrientation({
                    orientation: 'portrait_up'
                });
              }

            });
        </script>

原文出处：/show_1C7F8Rl802e.html