网页全屏及退出全屏

一、实现页面全屏

 1     function doFullscreen (el) {
 2       if (el == null) {
 3         el = document.documentElement
 4       }
 5       const func = el.requestFullscreen || el.requestFullScreen || el.webkitRequestFullScreen || el.mozRequestFullScreen || el.msRequestFullScreen
 6       if (!func) {
 7         throw new Error("您的浏览器不支持全屏模式");
 8       }
 9       func.call(el)
10     }

二、退出全屏

1     function doExitFullscreen () {
2       const func = document.exitFullscreen || document.exitFullScreen || document.webkitCancelFullScreen || document.mozCancelFullScreen || document.msExitFullscreen
3       func && func.call(document);
4     }

三、检测是否为全屏

1     function doCheckFullscreen () {
2       return !!(document.fullscreenElement || document.webkitFullscreenElement || document.mozFullScreenElement || document.msFullscreenElement)
3     }