<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        
    </style>
</head>
<body>
    <div style="margin-top:50px"> <!-- 设置margin-top是为了查看IE全屏前后的区别 -->
        <input type="button" value="FullScreen" onclick="fullScreen()" />
        <input type="button" value="ExitFullScreen" onclick="exitFullScreen()" />
    </div>

    <script>

        function fullScreen() {
            var el = document.documentElement;
            // -ms- ie
            // -moz- - firefox
            // -o- opera
            // -webkit- chrome 和 safari
            // requestFullscreen - 用于发出异步请求使元素进入全屏模式。
            var rfs = el.requestFullScreen || el.webkitRequestFullScreen ||
                el.mozRequestFullScreen || el.msRequestFullScreen;
            
            if(typeof rfs != "undefined" && rfs) {
                rfs.call(el);
            } else if(typeof window.ActiveXObject != "undefined") {
                //for IE，这里其实就是模拟了按下键盘的F11，使浏览器全屏
                var wscript = new ActiveXObject("WScript.Shell");
                if(wscript != null) {
                    wscript.SendKeys("{F11}");
                }
            }
        }

        function exitFullScreen() {
            var el = document;
            var cfs = el.cancelFullScreen || el.webkitCancelFullScreen || 
                el.mozCancelFullScreen || el.exitFullScreen;
            if(typeof cfs != "undefined" && cfs) {
                cfs.call(el);
            } else if(typeof window.ActiveXObject != "undefined") {
                //for IE，这里和fullScreen相同，模拟按下F11键退出全屏
                var wscript = new ActiveXObject("WScript.Shell");
                if(wscript != null) {
                    wscript.SendKeys("{F11}");
                }
            }
        }

    
    </script>
</body>
</html>