所以这个问题一直困扰着我几天。我一直在努力让我的网站上有一个工作的夜间模式开关。我在此之前和之后询问过我认为的解决方案，使用此站点和堆栈交换的帮助，我开始遇到一个恼人的问题。
以下是我的问题视频：https://ryan-simms.com/problem
只有在启用了nightmode并且我不明白实际问题是什么时才会出现问题。我每次都尝试过各种不同的JavaScript代码，结果相同。在有人说它是因为DOMContentLoaded位之前，我已经尝试在我的按钮上添加EventListeners时仅使用它来删除它。
此外，我尝试使用几种不同的方法更改getCookie（）的工作方式。
Cookie是正确的方式还是有更好的方法？
以下是我的HTML基础知识：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8"/>
<title>Ryan Simms</title>
<link id ="pageStyle" rel="stylesheet" href='css/lightStyle.css' type='text/css'>
<script src="scripts/lightSwitch.js"></script>
<script src="scripts/cookie.js"></script>
<link rel='stylesheet' href='https://fonts.googleapis.com/css?family=Roboto' type='text/css'>
</head>
<body>
<script src="lightSwitch.js"></script> <!-- Loads LightSwitch Script -->
<button type="button" id="lightSwitchOn">Turn On Night Mode</button>
<button type="button" id="lightSwitchOff">Turn Off Night Mode</button>
</body>
</html>
这是我的JavaScript：
document.addEventListener("DOMContentLoaded", handleDocumentLoad);
function handleDocumentLoad() {
var style = document.getElementById("pageStyle");
var offSwitch = document.getElementById("lightSwitchOff");
var onSwitch = document.getElementById("lightSwitchOn");
offSwitch.addEventListener('click', lightsOn);
onSwitch.addEventListener('click', lightsOff);
function lightsOff() {
document.cookie = "lights = off; expires = Fri, 31 Dec 9999 23:59:59 GMT";
style.setAttribute('href', 'css/darkStyle.css');
}
function lightsOn() {
document.cookie = "lights = on; expires = Fri, 31 Dec 9999 23:59:59 GMT";
style.setAttribute('href', 'css/lightStyle.css');
}
function getCookie( name ) {
var dc = document.cookie;
var prefix = name + "=";
var begin = dc.indexOf("; " + prefix);
var end = null;
if (begin == -1) {
begin = dc.indexOf(prefix);
if (begin != 0) return null;
end = document.cookie.indexOf(";", begin);
} else {
begin += 2;
end = document.cookie.indexOf(";", begin);
if (end == -1) {
end = dc.length;
}
}
return decodeURI(dc.substring(begin + prefix.length, end) ).replace(/"/g, '');
}
function checkCookie() {
var nightmode = getCookie("lights");
if (nightmode == "off") {
lightsOff();
} else {
lightsOn();
}
}
checkCookie();
}
这是我的默认CSS：
/*Layout for phones and tablets e.g. iPhone 5 and iPad*/
/*webpage fades in*/
html {
animation: fadein 2s;
position: relative;
min-height: 100%;
}
/*animation*/
@keyframes fadein {
from { opacity: 0; }
to { opacity: 1; }
}
/*main colour settings for page*/
body {
font-family: 'Roboto';
font-size: 22px;
color: #1C1C1C;
background-color: #FFF;
margin: 0 0 100px;
padding: 25px;
}
/*List in nav*/
li {
list-style-type: none;
display: inline;
}
/*Navigation*/
nav {
width: 100%;
background-color: #D8D8D8;
padding-top: 10px;
padding-bottom: 10px;
}
ol {
text-align: center;
margin-right: 10px;
}
/*Links*/
a, a:link, a:visited, a:hover {
color: #1C1C1C;
text-decoration: none;
}
/*Main heading*/
h1 {
position: relative;
margin: 0 auto;
text-align: center;
}
/*Images*/
img {
border: solid 0px #1C1C1C;
border-radius: 5px;
margin: 0 auto;
text-align: center;
}
label {
display: block;
margin-bottom: 10px;
margin-top: 10px;
}
textarea {
width: 300px;
height: 200px;
margin-bottom: 10px;
padding: 10px;
border: solid 1px #1C1C1C;
border-radius: 2px;
resize: none;
}
input {
border: solid 1px #1C1C1C;
border-radius: 2px;
padding: 5px;
}
#logo {
border: 0px;
display: inline;
position: absolute;
top: 40px;
left: 30px;
margin-left: 10px;
font-size: 40px;
}
#enter {
margin-top: 40px;
max-width: 90%;
max-height: 90%;
}
video {
max-width: 80%;
margin: 0 auto;
display: block;
}
/*Footer*/
footer {
position: absolute;
left: 0;
bottom: 0;
height: 100px;
width: 100%;
overflow: hidden;
text-align: center;
}
/*Main Body*/
#mainContent {
padding: 10px;
background-color: #D8D8D8;
margin-top: 10px;
}
#mainContent img {
display: inline;
max-width: 375px;
max-height: 375px;
float: right;
margin-right: 10px;
margin-left: 10px;
}
/*Light Switches*/
#lightSwitchOn {
display: inline;
position: absolute;
top: 40px;
right: 30px;
margin-right: 10px;
font-size: 40px;
}
#lightSwitchOff {
display: none;
position: absolute;
top: 40px;
right: 30px;
margin-right: 10px;
font-size: 40px;
}
#cookies {
position: fixed;
left: 0;
bottom: 0;
height: 8%;
width: 100%;
background-color: #D8D8D8;
padding-left: 30px;
}
/*Layout for device with a min-width of 1024px*/
@media only screen and (min-width: 1024px) {
#enter {
max-width: 60%;
max-height: 60%;
}
}
/*Layout for desktop with a min-width of 1280px (720p HD)*/
@media only screen and (min-width: 1280px) {
#enter {
max-width: 40%;
max-height: 40%;
}
}
/*Layout for desktop with a min-width of 1920px (1080p HD)*/
@media only screen and (min-width: 1920px) {
#enter {
max-width: 40%;
max-height: 40%;
}
}
启用夜间模式后我的CSS：
/*Layout for phones and tablets e.g. iPhone 5 and iPad*/
/*webpage fades in*/
html {
animation: fadein 2s;
position: relative;
min-height: 100%;
}
/*animation*/
@keyframes fadein {
from { opacity: 0; }
to { opacity: 1; }
}
/*main colour settings for page*/
body {
font-family: 'Roboto';
font-size: 22px;
color: #FFF;
background-color: black;
margin: 0 0 100px;
padding: 25px;
}
/*List in nav*/
li {
list-style-type: none;
display: inline;
}
/*Navigation*/
nav {
width: 100%;
background-color: #1C1C1C;
padding-top: 10px;
padding-bottom: 10px;
}
ol {
text-align: center;
margin-right: 10px;
}
/*Links*/
a, a:link, a:visited, a:hover {
color: #FFF;
text-decoration: none;
}
/*Main heading*/
h1 {
position: relative;
margin: 0 auto;
text-align: center;
}
/*Images*/
img {
max-width: 100%;
max-height: 100%;
border: solid 0px #FFF;
border-radius: 5px;
margin: 0 auto;
text-align: center;
}
label {
display: block;
margin-bottom: 10px;
margin-top: 10px;
}
textarea {
max-width: 100%;
max-height: 100%;
width: 300px;
height: 200px;
margin-bottom: 10px;
padding: 10px;
border: solid 1px #FFF;
border-radius: 2px;
resize: none;
}
input {
border: solid 1px #FFF;
border-radius: 2px;
padding: 5px;
}
#logo {
border: 0px;
display: inline;
position: absolute;
top: 40px;
left: 30px;
margin-left: 10px;
font-size: 40px;
}
#enter {
margin-top: 40px;
max-width: 90%;
max-height: 90%;
}
video {
max-width: 80%;
margin: 0 auto;
display: block;
}
/*Footer*/
footer {
position: absolute;
left: 0;
bottom: 0;
height: 100px;
width: 100%;
overflow: hidden;
text-align: center;
}
/*Main Body*/
#mainContent {
padding: 10px;
background-color: #1C1C1C;
margin-top: 10px;
}
#mainContent img {
display: inline;
max-width: 375px;
max-height: 375px;
float: right;
margin-right: 10px;
margin-left: 10px;
}
/*Light Switches*/
#lightSwitchOn {
display: none;
position: absolute;
top: 40px;
right: 30px;
margin-right: 10px;
font-size: 20px;
}
#lightSwitchOff {
display: inline;
position: absolute;
top: 40px;
right: 30px;
margin-right: 10px;
font-size: 20px;
}
#cookies {
position: fixed;
left: 0;
bottom: 0;
height: 8%;
width: 100%;
background-color: #1C1C1C;
padding-left: 30px;
}
/*Layout for device with a min-width of 1024px*/
@media only screen and (min-width: 1024px) {
#enter {
max-width: 60%;
max-height: 60%;
}
}
/*Layout for desktop with a min-width of 1280px (720p HD)*/
@media only screen and (min-width: 1280px) {
#enter {
max-width: 40%;
max-height: 40%;
}
}
/*Layout for desktop with a min-width of 1920px (1080p HD)*/
@media only screen and (min-width: 1920px) {
#enter {
max-width: 40%;
max-height: 40%;
}
}
答案 0 :(得分：1)
Cookie是正确的方式还是有更好的方式？
由于您不关心服务器端的Cookie，因此请选择localStorage。您可以使用
localStorage.setItem('lights', 'off');
if(localStorage.getItem('lights') === 'off') { ... }
如果您的夜间模式已启用，请考虑在夜间模式下为.dark添加body课程，并在主样式表中加入相应的更改。
body {
font-family: 'Roboto';
font-size: 22px;
color: #1C1C1C;
background-color: #FFF;
margin: 0 0 100px;
padding: 25px;
}
body.dark {
color: #FFF;
background-color: black;
}
/*Navigation*/
nav {
width: 100%;
background-color: #D8D8D8;
padding-top: 10px;
padding-bottom: 10px;
}
.dark nav {
background-color: #1C1C1C;
}