超简单的给网站添加夜间模式
代码语言:javascript复制let brightness = 0;//显示遮罩
let div;
function cover(brightness) {
if (typeof (div) === 'undefined') {
div = document.createElement('div');
div.setAttribute('style', 'position:fixed;top:0;left:0;outline:50000px solid;z-index:99999;');
document.body.appendChild(div);
} else {
div.style.display = '';
}
div.style.outlineColor = 'rgba(0,0,0,' brightness ')';
}
window.addEventListener('keydown', function (e) {//事件监听
if (e.altKey && e.keyCode === 90) {//Alt Z 关灯
cover(brightness = 0.3);
}
if (e.altKey && e.keyCode === 88) {//Alt X 开灯
cover(brightness = 0);
}
if (e.altKey && e.keyCode === 38) {//Alt ↑ 亮度调高
if (brightness - 0.05 > 0.05) {
cover(brightness -= 0.05);
}
}
if (e.altKey && e.keyCode === 40) {//Alt ↓ 亮度调低
if (brightness 0.05 < 0.95) {
cover(brightness = 0.05);
}
}
}, false);