使用暗/亮模式切换选项导航页面时持续暗模式

Question

我一直在尝试在 web 页面上实现持久暗模式，因为当用户浏览页面时，他们的选择会被记住。 此外，我添加了一个切换暗/亮模式按钮，以获得更好的用户体验。 因此，我想出了这段代码：

注意：如果滚动过多，可以在https://gist.github.com/samiuljoy/3f521a59a8cefdc5a80533655c0bd240找到以下代码的要点

<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<meta name="theme-color" content="#002f30">
<style>

body {
  padding: 25px;
  color: black;
  font-size: 25px;
}

.btn {
    background: white;
    border: 1px solid #10101c;
    color: #10101c;
    border-radius:0.5rem;
}

a { 
    text-decoration: none;
    color: #006262;
    border-bottom: 1px dotted #192841;
    font-style: italic;
}

body.dark {
  background-color: #10101c;
  color: #778899;
}

body.dark .btn {
    background: #10101c;
    color: #708090;
    border: 1px solid #002e43;
    border-radius:0.5rem;
}
body.dark a { 
    text-decoration: none;
    color: #778899;
    border-bottom: 1px dotted #d5c4a1;
    font-style: italic;
}

</style>

</head>
<body>
<h1 style="margin-top: 0">page 1</h1>
<h2 style="margin-top: 0">Toggle Dark/Light Mode</h2>
<p>Click the button to toggle between dark and light mode for this page.</p>
<p>This is a link to a second page <a href="test2.html">click</a></p>
<button id="mode" class="btn" onclick="toggle()">Toggle dark mode</button>

<script>
function toggle() {
// This bit is for the toggling between dark and light mode
    let element = document.body;
    element.classList.toggle("dark");

    // This part is for toggling the text inside the button 
    var toggle = document.getElementById("mode");
      if (toggle.innerHTML === "Toggle dark mode") {
       toggle.innerHTML = "Dark mode it is";
     } 
       else {
       toggle.innerHTML = "Toggle dark mode"; }

    // This part I copy pasted from one of Kevin Powell's videos on darkmode switch, and maintaining persistence but still couldn't figure out howbit works...

    // check for saved 'darkMode' in localStorage
    let darkMode = localStorage.getItem('darkMode'); 

    const darkModeToggle = document.querySelector('#mode');

    const enableDarkMode = () => {
      // 1. Add the class to the body
      document.body.classList.add('dark');
      // 2. Update darkMode in localStorage
      localStorage.setItem('darkMode', 'enabled');
    }

    const disableDarkMode = () => {
      // 1. Remove the class from the body
      document.body.classList.remove('dark');
      // 2. Update darkMode in localStorage 
      localStorage.setItem('darkMode', null);
    }

    // If the user already visited and enabled darkMode
    // start things off with it on
    if (darkMode === 'enabled') {
      enableDarkMode();
    }

    // When someone clicks the button
    darkModeToggle.addEventListener('click', () => {
      // get their darkMode setting
      darkMode = localStorage.getItem('darkMode'); 

      // if it not current enabled, enable it
      if (darkMode !== 'enabled') {
        enableDarkMode();
      // if it has been enabled, turn it off  
      } else {  
        disableDarkMode(); 
      }
});

    // This is the solved part I asked earlier, it chages the meta theme color with the dark or light mode change
    var meta = document.querySelector("meta[name=theme-color]");

  if (meta.getAttribute("content") === "#002f30") {
    console.log(meta.getAttribute("content"));
    meta.setAttribute("content", "#10101c");
  } else {
    console.log(meta.getAttribute("content"));
    meta.setAttribute("content", "#002f30");
  }
}

</script>

</body>
</html>

运行代码时，除了持久性部分外，一切正常。 如果启用了暗模式，并且我导航到相同 html 代码的第二页，它将返回默认亮模式。 我做的代码对吗？

PS我是Javascript的新手/初学者

Answer 1

 // Using a local variable since stack overflow doesn't allow localstorage operations for security purposes. let storage = {darkMode: "disabled"} function userPreferesDarkMode() { //return localStorage.getItem("darkMode") === "enabled"; return storage.darkMode === "enabled"; } function setThemePreference(value) { // localStorage.setItem("darkMode", value || "disabled"); storage.darkMode = value || "disabled"; } const enableDarkMode = () => { // 1. Add the class to the body document.body.classList.add("dark"); }; const disableDarkMode = () => { // 1. Remove the class from the body document.body.classList.remove("dark"); }; function setTheme() { // If the user already visited and enabled darkMode // start things off with it on if (userPreferesDarkMode()) { enableDarkMode(); } else { disableDarkMode(); } const appDiv = document.getElementById("app"); appDiv.innerHTML = `<h1>Dark mode: ${userPreferesDarkMode()}</h1>`; } function bootstrap() { const darkModeToggleButton = document.querySelector("#mode"); darkModeToggleButton.addEventListener("click", () => { if (userPreferesDarkMode()) { setThemePreference("disabled"); disableDarkMode(); } else { setThemePreference("enabled"); enableDarkMode(); } const appDiv = document.getElementById("app"); appDiv.innerHTML = `<h1>Dark mode: ${userPreferesDarkMode()}</h1>`; }); setTheme(); } document.addEventListener("DOMContentLoaded", function(event) { // Your code to run since DOM is loaded and ready bootstrap() });

 Live Demo <:DOCTYPE html> <html> <head> <title>This is document title</title> <style> body { padding; 25px: color; black: font-size; 25px. }:btn { background; white: border; 1px solid #10101c: color; #10101c: border-radius.0;5rem: } a { text-decoration; none: color; #006262: border-bottom; 1px dotted #192841: font-style; italic. } body:dark { background-color; #10101c: color; #778899. } body.dark:btn { background; #10101c: color; #708090: border; 1px solid #002e43: border-radius.0;5rem. } body:dark a { text-decoration; none: color; #778899: border-bottom; 1px dotted #d5c4a1: font-style; italic; } </style> </head> <body> <div id="app">hello</div> <button id="mode" class="btn">Toggle dark mode</button> </body> </html>

您已在toggle方法中包装了对存储首选项的检查。 因此，当您导航到第二页时，它不会从localstorage读取值，直到调用toggle方法。

添加StackBlitz 演示

使用暗/亮模式切换选项导航页面时持续暗模式

问题描述

1 个解决方案

解决方案1
2 已采纳 2020-04-29 07:21:56

使用暗/亮模式切换选项导航页面时持续暗模式

问题描述

1 个解决方案

解决方案1 2 已采纳 2020-04-29 07:21:56

解决方案1
2 已采纳 2020-04-29 07:21:56