js全屏，监听页面是否全屏

// 检测页面是否处于全屏模式
function isPageFullscreen() {
    return !!(document.fullscreenElement || document.mozFullScreenElement || document.webkitFullscreenElement || document.msFullscreenElement);
}
 
// 监听全屏状态变化
document.addEventListener('fullscreenchange', function () {
    if (isPageFullscreen()) {
        console.log('页面已进入全屏模式');
    } else {
        console.log('页面已退出全屏模式');
    }
});
 
// 进入全屏
function requestFullscreen(element) {
    if (element.requestFullscreen) {
        element.requestFullscreen();
    } else if (element.mozRequestFullScreen) {
        element.mozRequestFullScreen();
    } else if (element.webkitRequestFullscreen) {
        element.webkitRequestFullscreen();
    } else if (element.msRequestFullscreen) {
        element.msRequestFullscreen();
    }
}
 
// 退出全屏
function exitFullscreen() {
    if (document.exitFullscreen) {
        document.exitFullscreen();
    } else if (document.mozCancelFullScreen) {
        document.mozCancelFullScreen();
    } else if (document.webkitExitFullscreen) {
        document.webkitExitFullscreen();
    } else if (document.msExitFullscreen) {
        document.msExitFullscreen();
    }
}
 
// 示例：点击按钮进入/退出全屏
const fullscreenButton = document.getElementById('fullscreen-button');
fullscreenButton.addEventListener('click', function () {
    if (isPageFullscreen()) {
        exitFullscreen();
    } else {
        requestFullscreen(document.documentElement);
    }
});