js使网页全屏

function enterFullScreen() {
    const elem = document.documentElement;
    if (elem.requestFullscreen) {
        elem.requestFullscreen();
    } else if (elem.mozRequestFullScreen) { /* Firefox */
        elem.mozRequestFullScreen();
    } else if (elem.webkitRequestFullscreen) { /* Chrome, Safari & Opera */
        elem.webkitRequestFullscreen();
    } else if (elem.msRequestFullscreen) { /* IE/Edge */
        elem.msRequestFullscreen();
    }
}

// 调用函数进入全屏
document.getElementById('fullscreen-button').addEventListener('click', enterFullScreen);

function exitFullScreen() {
    if (document.exitFullscreen) {
        document.exitFullscreen();
    } else if (document.mozCancelFullScreen) { /* Firefox */
        document.mozCancelFullScreen();
    } else if (document.webkitExitFullscreen) { /* Chrome, Safari & Opera */
        document.webkitExitFullscreen();
    } else if (document.msExitFullscreen) { /* IE/Edge */
        document.msExitFullscreen();
    }
}

// 调用函数退出全屏
document.getElementById('exit-fullscreen-button').addEventListener('click', exitFullScreen);