浏览器全屏事件

    entryFullScreen() {
      let doe = document.documentElement;
      if(doe.requestFullScreen) {
        doe.requestFullScreen();
      }else if(doe.webkitRequestFullScreen) {
        doe.webkitRequestFullScreen()
      } else if (doe.mozRequestFullScreen) {
        doe.mozRequestFullScreen();
      } 
    },
    exitFullScreen() {
      var docE = document;
      if (docE.exitFullscreen) {
        docE.exitFullscreen();
      } else if (docE.mozCancelFullScreen) {
        docE.mozCancelFullScreen();
      } else if (docE.webkitCancelFullScreen) {
        docE.webkitCancelFullScreen();
      }
    }