<script>
var brightness;
//显示遮罩
function cover(brightness) {
if (typeof(div) == 'undefined') {
div = document.createElement('div');
div.setAttribute('style', 'position:fixed;top:0;left:0;outline:5000px solid;z-index:99999;');
document.body.appendChild(div);
} else {
div.style.display = '';
}
div.style.outlineColor = 'rgba(0,0,0,' + brightness + ')';
}
//事件监听
window.addEventListener('keydown', function(e) {
if (e.altKey && e.keyCode == 90) { //Alt+Z:打开夜间模式
cover(brightness = 0.3);
}
if (e.altKey && e.keyCode == 88) { //Alt+X:关闭
cover(brightness = 0);
}
if (e.altKey && e.keyCode == 38) { //Alt+↑:增加亮度
if (brightness - 0.05 > 0.05) cover(brightness -= 0.05);
}
if (e.altKey && e.keyCode == 40) { //Alt+↓:降低亮度
if (brightness + 0.05 < 0.95) cover(brightness += 0.05);
}
}, false);
</script>本站可以做测试
