如何在iOS上获得JavaScript requestFullscren的工作

Question

我有全屏模式的功能。它除了iOS之外，还涉及所有浏览器和Android设备。

如何在iOS设备浏览器中进入全屏模式？

var toggleFullScreen = function(mode) {
    if (mode) {
        var element = document.documentElement;
        if(element.requestFullscreen) {
            element.requestFullscreen();
        } else if(element.mozRequestFullScreen) {
            element.mozRequestFullScreen();
        } else if(element.webkitRequestFullscreen) {
            element.webkitRequestFullscreen();
        } else if(element.msRequestFullscreen) {
            element.msRequestFullscreen();
        }
    } else {
        if(document.exitFullscreen) {
            document.exitFullscreen();
        } else if(document.mozCancelFullScreen) {
            document.mozCancelFullScreen();
        } else if(document.webkitExitFullscreen) {
            document.webkitExitFullscreen();
        }
    }
};