主题切换按钮(js)在第一次加载页面时不起作用。

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英文:

Theme toggle button (js) does not work on very first page load

问题

我正在构建一个非常简单的GitHub页面作为简历(我不是Web开发人员),但在首次加载网站时,出现了一个奇怪的问题。

我有一个切换按钮,可以切换主题为暗/亮。当我首次访问这个网站(或在清除缓存和Cookie后再次访问)时,我可以切换到亮主题,但无法切换回暗主题(原始主题)。刷新网站后,一切都正常。

我使用JS来切换主题(但代码本身似乎不是问题):

// 从本地存储中检查用户的主题首选项
const currentTheme = localStorage.getItem('theme');
if (currentTheme) {
  body.classList.add(currentTheme);
  updateThemeLabel(currentTheme);
}

themeToggle.addEventListener('change', () => {

  if (body.classList.contains('light-mode')) {
    // 如果当前主题是亮主题,请切换到暗主题
    body.classList.replace('light-mode', 'dark-mode');
    updateThemeLabel('dark-mode'); // 更新主题标签的文本和颜色
    localStorage.setItem('theme', 'dark-mode');
  } else {
    // 如果当前主题是暗主题,请切换到亮主题
    body.classList.replace('dark-mode', 'light-mode');
    updateThemeLabel('light-mode'); // 更新主题标签的文本和颜色
    localStorage.setItem('theme', 'light-mode');
  }
});

function updateThemeLabel(theme) {
  if (theme === 'dark-mode') {
    themeLabel.textContent = '炫目模式';
    themeLabel.style.color = '#fff';
    footer.style.color = '#fff';
    footer.style.backgroundColor = '#333';
    body.style.backgroundColor = '#333';
    body.style.color = '#fff';
    socialIconTwitter.style.color = '#fff';
    socialIconLinkedin.style.color = '#fff';
  } else {
    themeLabel.textContent = '快速返回!';
    themeLabel.style.color = '#000';
    footer.style.color = '#000';
    footer.style.backgroundColor = '#fff';
    body.style.backgroundColor = '#fff';
    body.style.color = '#000';
    socialIconTwitter.style.color = '#000';
    socialIconLinkedin.style.color = '#000';
  }
}

希望这对你有所帮助。

英文:

I am building a very simple GitHub page as a CV (I am not a web developer) and I have a strange issue with the behavior of website when it is loaded very first time.

I have a toggle button that switches themes to dark/light. When I visit this website very first time (or after cache a cookies clearing) I can switch to light but not back to dark (original). After refresh of website everything works just fine.

I use JS to toggle theme (but code itself does not seem to be a problem):

// Check the user's theme preference from local storage
const currentTheme = localStorage.getItem('theme');
if (currentTheme) {
body.classList.add(currentTheme);
updateThemeLabel(currentTheme); 
}
themeToggle.addEventListener('change', () => {
if (body.classList.contains('light-mode')) {
// If the current theme is light, switch to dark
body.classList.replace('light-mode', 'dark-mode');
updateThemeLabel('dark-mode'); // Update the theme label text and color
localStorage.setItem('theme', 'dark-mode');
} else {
// If the current theme is dark, switch to light
body.classList.replace('dark-mode', 'light-mode');
updateThemeLabel('light-mode'); // Update the theme label text and color
localStorage.setItem('theme', 'light-mode');
}
});
function updateThemeLabel(theme) {
if (theme === 'dark-mode') {
themeLabel.textContent = 'Burn your eyes';
themeLabel.style.color = '#fff'; 
footer.style.color = '#fff'; 
footer.style.backgroundColor = '#333'; 
body.style.backgroundColor = '#333'; 
body.style.color = '#fff';
socialIconTwitter.style.color = '#fff';
socialIconLinkedin.style.color = '#fff';
} else {
themeLabel.textContent = 'Quickly back!';
themeLabel.style.color = '#000'; 
footer.style.color = '#000'; 
footer.style.backgroundColor = '#fff'; 
body.style.backgroundColor = '#fff';
body.style.color = '#000';
socialIconTwitter.style.color = '#000';
socialIconLinkedin.style.color = '#000';
}
}

答案1

得分: 1

这始终为false

if (body.classList.contains('light-mode'))

直到用户选择了某些内容 并重新加载页面,在此时你在此处设置一个类:

body.classList.add(currentTheme);

但是你从不在change事件处理程序中添加该类。相反,你这样做:

body.classList.replace('dark-mode', 'light-mode');

但如果classList 不包含 'dark-mode',那么就没有什么可以替换的了。

取而代之,删除和添加类。例如:

themeToggle.addEventListener('change', () => {

  if (body.classList.contains('light-mode')) {
    body.classList.remove('light-mode'); // 移除浅色模式
    body.classList.add('dark-mode'); // 添加深色模式
    updateThemeLabel('dark-mode');
    localStorage.setItem('theme', 'dark-mode');
  } else {
    body.classList.remove('dark-mode'); // 移除深色模式
    body.classList.add('light-mode'); // 添加浅色模式
    updateThemeLabel('light-mode');
    localStorage.setItem('theme', 'light-mode');
  }
});
英文:

This is always false:

if (body.classList.contains('light-mode'))

Until the user selects something and reloads the page, at which time you set a class here:

body.classList.add(currentTheme);

But you never add that class in the change event handler. Instead, you do this:

body.classList.replace('dark-mode', 'light-mode');

But if the classList doesn't contain 'dark-mode' then there's nothing to replace.

Instead, remove and add the classes. For example:

themeToggle.addEventListener('change', () => {
if (body.classList.contains('light-mode')) {
body.classList.remove('light-mode'); // remove light mode
body.classList.add('dark-mode'); // add dark mode
updateThemeLabel('dark-mode');
localStorage.setItem('theme', 'dark-mode');
} else {
body.classList.remove('dark-mode'); // remove dark mode
body.classList.add('light-mode'); // add light mode
updateThemeLabel('light-mode');
localStorage.setItem('theme', 'light-mode');
}
});

huangapple
  • 本文由 发表于 2023年7月27日 22:34:19
  • 转载请务必保留本文链接:https://go.coder-hub.com/76780800.html
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