JS实现全屏和点击按钮退出全屏写法分享

本代码是分享JS实现全屏和点击按钮退出全屏写法，一个按钮实现点击全屏，再点击退出全屏；同时支持F11按键。

HTML部分：

<button id="bt" onclick="toggleFullScreen(event)">点我全屏</button>

JS部分：

<script>
 document.onkeydown=function(e){
        e = e|| window.event || arguments.callee.caller.arguments[0];
        if(e && e.keyCode==122){
            document.getElementById('bt').onclick();
            e.preventDefault();
            e.stopPropagation();
        }
    }
    function FullScreen(el) {
        var isFullscreen = document.fullScreen || document.mozFullScreen || document.webkitIsFullScreen;
        if (!isFullscreen) {//进入全屏,多重短路表达式
            (document.body.requestFullscreen && document.body.requestFullscreen()) ||
            (document.body.mozRequestFullScreen && document.body.mozRequestFullScreen()) ||
            (document.body.webkitRequestFullscreen && document.body.webkitRequestFullscreen()) ||
            (document.body.msRequestFullscreen && document.body.msRequestFullscreen());
 
        } else {	//退出全屏,三目运算符
            document.exitFullscreen ? document.exitFullscreen() :
                document.mozCancelFullScreen ? document.mozCancelFullScreen() :
                    document.webkitExitFullscreen ? document.webkitExitFullscreen() : '';
        }
    }
    function toggleFullScreen(e) {
        var el = e.srcElement || e.target;//target兼容Firefox
        FullScreen(el);
    }
</script>