刷新页面后，如何阻止 CSS 样式表重置为默认值？

Question

I have this piece of code:

 $(document).ready(function() { $(".lightDark").hide(); $("#changeTheme").click(function() { $(".lightDark").toggle("slow"); }); // Switch theme $('#lightTheme').click(function() { $('link[href="darkMode.css"]').attr('href','lightMode.css'); }); $('#darkTheme').click(function() { $('link[href="lightMode.css"]').attr('href','darkMode.css'); }); });

 body { background-color: black; } .changeThemeButtons { float: right; margin-top: 50px; margin-right: 50px; border:2px solid white; border:none; color:white; } .changeThemeButtons td { font-family: 'Open Sans Condensed', sans-serif; font-size: 1.6em; text-transform: uppercase; color:white; text-align: center; } .changeThemeButtons th { background-color: #733FFF; border-radius: 100px; height:200px; width:200px; } #changeTheme { cursor: pointer; } #changeTheme i { color:#f00; } #darkTheme { color:black; margin-right: 50px; } #lightTheme { color:white; }

 <script src="https://kit.fontawesome.com/c22b2f5999.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <link rel="stylesheet" id="darkMode" href="darkMode.css"> <div class="block two"> <nav> <a href="#about">About me</a> <a href="#myWork">My Work</a> <a href="#services">Services</a> <a href="#contact">Contact</a> </nav> <table class="changeThemeButtons" align="right"> <tr> <td><a id="changeTheme">Change Theme &nbsp;<i class="fas fa-caret-down"></i></a></td> </tr> <tr> <th class="lightDark"> <a href="#" id="darkTheme"><i class="fas fa-circle fa-3x"></i></a> <a href="#" id="lightTheme"><i class="fas fa-circle fa-3x"></i></a> </th> </tr> </table>

Everything works fine, until the point where you're on lightMode.css and let's say you refresh the page, then it would reset to the darkMode.css. I have tried to remove the default darkMode.css from HTML (with JQuery), but it doesn't seem to work. I need it to stay to lightMode (if selected) until you'd click again to change to darkMode manually.

Answer 1

Just put your theme css in a css file and pass it to the function, On page load the if (localStorage.getItem("theme") != "") checks if theme has been set.. Here you have an example:

 if (localStorage.getItem("theme") != "") { loadcssfile(localStorage.getItem("theme")); } function loadcssfile(filename) { if (filename != "") { localStorage.setItem("theme", filename); } var fileref = document.createElement("link"); fileref.setAttribute("rel", "stylesheet"); fileref.setAttribute("type", "text/css"); fileref.setAttribute("href", filename); if (typeof fileref != "undefined") document.getElementsByTagName("head")[0].appendChild(fileref); }

 <div onclick="loadcssfile('css/pink.css')" id="pink"> Pink </div> <div onclick="loadcssfile('css/blue.css')" id="blue"> Blue </div>

Answer 2

1. You need to provide a default theme for first time visitor.
2. You need to store the user selection somewhere (cookie, local storage or database etc.)
3. On on document ready, read the user's preferred theme from your storage and apply the corresponding css file. If there is no preference, just leave the default theme.

Answer 3

You may do something like below to store the value in localstorage:

 $(document).ready(function() { const theme = localStorage.getItem('mode'); console.log(theme); if(theme){ $('link[id="darkMode"]').attr('href',theme); } $("#changeTheme").click(function() { $(".lightDark").toggle("slow"); }); // Switch theme $('#lightTheme').click(function() { $('link[id="darkMode"]').attr('href','lightMode.css'); localStorage.setItem('mode','lightMode.css'); }); $('#darkTheme').click(function() { $('link[id="darkMode"]').attr('href','darkMode.css'); localStorage.setItem('mode','darkMode.css'); }); });