更改主题时更改徽标（和其他 icon.svg）

Question

我是一个新手，试图从移动优先开始构建投资组合页面。 我刚刚了解了集成偏好颜色方案媒体查询，但在添加之前，我想让用户选择在我的网页中的暗/亮模式之间切换。 我已经添加了一个 javascript 可以做到这一点。

我希望我的 logo 和 icons.svg 在我切换主题时也发生变化

你可以看看我链接的codepen。

您可以按照以下步骤测试问题：

1. 进入菜单 --> 点击切换到灯光模式
2. 徽标发生了变化，但是当我切换回深色模式时它不会变回来。
3. 我也有同样的问题，当我点击徽标时，在浅色模式下，它会更改为默认的深色模式徽标。

我假设如果我知道如何让这个仅用于徽标，我也可以对其他图标使用相同的技术。

如何让它工作？

Check the codepen link to my problem 对于我的 codepen 中我的 svg 的长而令人不安的 base64 数据，我不知道还能做什么。

const toggleSwitch = document.querySelector('.theme-switch input[type="checkbox"]');

function switchTheme(e) {
  if (e.target.checked) {
    document.documentElement.setAttribute('data-theme', 'dark');
  } else {
    document.documentElement.setAttribute('data-theme', 'light');
  }
}

toggleSwitch.addEventListener('change', switchTheme, false);



/*This is to store the light or dark mode preferences for future visits*/

function switchTheme(e) {
  if (e.target.checked) {
    document.documentElement.setAttribute('data-theme', 'dark');
    localStorage.setItem('theme', 'dark'); //add this
  } else {
    document.documentElement.setAttribute('data-theme', 'light');
    localStorage.setItem('theme', 'light'); //add this
  }
}

/*to check for saved preferences on load of the site*/

const currentTheme = localStorage.getItem('theme') ? localStorage.getItem('theme') : null;

if (currentTheme) {
  document.documentElement.setAttribute('data-theme', currentTheme);

  if (currentTheme === 'dark') {
    toggleSwitch.checked = true;
  }
}

function changeImage() {
  var image = document.getElementById('mylogo');
  if (image.src.match("images/LOGO_SN_over_black.svg")) {
    image.src = "images/LOGO_SN.svg";
  } else {
    image.src = "images/LOGO_SN.svg";
  }
}

:root {
  --background-color: #262626;
  --mainfontcolor: #f7f7f2;
  --hightlightcolor: #01BAEF;
}

[data-theme="dark"] {
  --background-color: #f7f7f2;
  --mainfontcolor: #262626;
  --hightlightcolor: #01BAEF;
}

body {
  background-color: var(--background-color);
  font-family: 'Lato', sans-serif;
  line-height: 1.5;
}


/*Navigation panel*/

.logo-header img {
  position: absolute;
  top: 1.2em;
  left: 2em;
  max-width: 3em;
  opacity: 0.9;
  z-index: 9999;
}

header {
  background: var(--background-color);
  height: 5em;
  position: fixed;
  top: 0;
  -webkit-transition: top 0.2s ease-in-out;
  -moz-transition: top 0.2s ease-in-out;
  -o-transition: top 0.2s ease-in-out;
  transition: top 0.2s ease-in-out;
  width: calc(100vw);
  z-index: 90;
}


/*menu bar styles start here*/

.menu-wrap {
  position: fixed;
  top: 0;
  right: 0;
  z-index: 99;
}

.menu-wrap .toggler {
  position: absolute;
  top: 2.5em;
  right: 3.1em;
  cursor: pointer;
  opacity: 0;
  width: 4.2em;
  height: 2em;
  z-index: 100;
}

.menu-wrap .hamburger {
  position: absolute;
  top: 1.8em;
  right: 2em;
  z-index: 99;
  width: 4em;
  height: 2em;
  padding: 1em;
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-align: center;
  -moz-box-align: center;
  -ms-flex-align: center;
  -ms-box-align: center;
  align-items: center;
  -webkit-box-pack: center;
  -moz-box-pack: center;
  -ms-box-pack: center;
  -ms-flex-pack: center;
  justify-content: center;
}


/*hamburger line */

.menu-wrap .hamburger>div {
  position: relative;
  -webkit-box-flex: 0;
  -moz-box-flex: 0;
  -ms-flex: none;
  flex: none;
  width: 100%;
  height: 0.1em;
  background-color: var(--mainfontcolor);
  opacity: 0.9;
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-align: center;
  -moz-box-align: center;
  -ms-box-align: center;
  -ms-flex-align: center;
  align-items: center;
  -webkit-box-pack: center;
  -moz-box-pack: center;
  -ms-box-pack: center;
  -ms-flex-pack: center;
  justify-content: center;
  -webkit-transition: all 0.5s ease;
  transition: all 0.5s ease;
}

.menu-wrap .hamburger>div::before,
.menu-wrap .hamburger>div::after {
  content: '';
  position: absolute;
  z-index: 99;
  top: -0.6em;
  width: 100%;
  height: 0.1em;
  background-color: var(--mainfontcolor);
}

.menu-wrap .hamburger>div:after {
  top: 0.6em;
}


/*toggle animate*/

.menu-wrap .toggler:checked+.hamburger>div {
  -webkit-transform: rotate(135deg);
  transform: rotate(135deg);
}


/* Turns Lines Into X */

.menu-wrap .toggler:checked+.hamburger>div:before,
.menu-wrap .toggler:checked+.hamburger>div:after {
  top: 0;
  -webkit-transform: rotate(90deg);
  transform: rotate(90deg);
}


/* Rotate On Hover When Checked */

.menu-wrap .toggler:checked:hover+.hamburger>div {
  -webkit-transform: rotate(225deg);
  transform: rotate(225deg);
}


/* To Show the Menu */

.menu-wrap .toggler:checked~.menu {
  visibility: visible;
}

.menu-wrap .toggler:checked~.menu>div {
  -webkit-transform: scale(1);
  transform: scale(1);
  -webkit-transition-duration: 0.4s;
  transition-duration: 0.4s;
}

.menu-wrap .toggler:checked~.menu>div>div {
  opacity: 1;
  -webkit-transition: opacity 0.3s ease 0.3s;
  transition: opacity 0.3s ease 0.3s;
  -webkit-transition: opacity 0.4s ease 0.3s;
  -moz-transition: opacity 0.3s ease 0.3s;
  -o-transition: opacity 0.3s ease 0.3s;
}

.menu-wrap .menu {
  position: relative;
  top: 0;
  right: 0;
  width: calc(100vw);
  height: calc(100vh);
  visibility: hidden;
  overflow: hidden;
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-align: center;
  -ms-flex-align: center;
  align-items: center;
  -webkit-box-pack: center;
  -ms-flex-pack: center;
  justify-content: center;
  -webkit-backface-visibility: hidden;
  background-color: var(--background-color);
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
}

.menu-wrap .menu>div {
  background-color: var(--background-color);
  border-radius: 0%;
  width: 100vw;
  height: 100vh;
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-flex: 0;
  -ms-flex: none;
  flex: none;
  -webkit-box-align: center;
  -ms-flex-align: center;
  align-items: center;
  -webkit-box-pack: center;
  -ms-flex-pack: center;
  justify-content: center;
  -webkit-transform: scale(0);
  transform: scale(0);
  transition: all 0.4s ease;
  -webkit-transition: all 0.4s ease;
  -moz-transition: all 0.4s ease;
  -o-transition: all 0.4s ease;
}

.menu-wrap .menu>div>div {
  text-align: center;
  max-width: calc(100vw);
  max-height: calc(100vh);
  opacity: 0;
  transition: opacity 0.3s ease;
  -webkit-transition: opacity 0.3s ease;
  -moz-transition: opacity 0.3s ease;
  -o-transition: opacity 0.3s ease;
  padding-top: 1.5em;
}

.menu-wrap .menu>div>div>ul>li {
  list-style: none;
  color: var(--mainfontcolor);
  font-size: 1.4em;
  padding: 0.8em;
}

.menu-wrap .menu>div>div>ul>li>a {
  color: var(--mainfontcolor);
  opacity: 0.9;
  text-decoration: none;
  transition: color 0.3s ease;
  -webkit-transition: color 0.3s ease;
  -moz-transition: color 0.3s ease;
  -o-transition: color 0.3s ease;
}


/*Main page content*/

.mainpage-container {
  font-family: 'Lato', sans-serif;
  color: var(--mainfontcolor);
  margin-top: 5em;
  text-align: center;
  overflow: hidden;
  max-width: 100vw;
}

.mainpage-section2 {
  margin-top: 1em;
}

.content-image {
  width: calc(100vw);
  height: calc(95vh);
  background-image: url('https://st.depositphotos.com/1695366/1398/v/450/depositphotos_13980191-stock-illustration-cartoon-woman-writing-new-years.jpg');
  background-repeat: no-repeat;
  background-position: right;
  background-size: cover;
}

.mainpage-text {
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-orient: vertical;
  -webkit-box-direction: normal;
  -ms-flex-direction: column;
  flex-direction: column;
  -webkit-box-align: center;
  -ms-flex-align: center;
  align-items: center;
  -webkit-box-pack: center;
  -ms-flex-pack: center;
  justify-content: center;
}

.mainpage-text h1 {
  font-family: "Lato", sans-serif;
  font-size: 2rem;
  font-weight: 400;
  color: var(--mainfontcolor);
  text-align: center;
  line-height: 1.5;
  padding-top: 3em;
  padding-bottom: 0.5em;
  padding-left: 1.2rem;
  padding-right: 1.2rem;
  opacity: 0.9;
}

.mainpage-text h2 {
  font-family: "Lato", sans-serif;
  font-size: 1.1rem;
  font-weight: 100;
  color: var(--mainfontcolor);
  opacity: 0.8;
  text-align: center;
  line-height: 1.5;
  padding-left: 1.2rem;
  padding-right: 1.2rem;
  padding-top: 0.5em;
  padding-bottom: 2.5em;
}

.mainpage-text p {
  padding-left: 1.2rem;
  padding-right: 1.2rem;
  padding-top: 1.5em;
  padding-bottom: 2em;
  transition: color 0.3s ease;
}

.contact-link {
  text-decoration: none;
  font-family: "Lato", sans-serif;
  font-size: 1rem;
  font-weight: 100;
  color: var(--mainfontcolor);
  opacity: 0.8;
  text-align: center;
  line-height: 1.5;
  position: relative;
}

.mainpage-text p :hover {
  color: var(--hightlightcolor);
}

.contact-link::before {
  border-top: 0.05em dotted var(--mainfontcolor);
  content: '';
  position: absolute;
  right: 0;
  top: 1.2em;
  left: 0;
}


/*toggle to dark or light mode*/

.theme-switch-wrapper {
  display: flex;
  align-items: center;
}

.theme-switch-wrapper em {
  margin-left: 0.5em;
  margin-right: 0.5em;
}

.theme-switch-wrapper img {
  width: 1em;
  padding-top: 0.3em;
}

.theme-switch {
  display: inline-block;
  height: 1.5em;
  position: relative;
  width: 2.6em;
}

.theme-switch input {
  display: none;
}

.slider {
  background-color: #ccc;
  bottom: 0;
  cursor: pointer;
  left: 0;
  position: absolute;
  right: 0;
  top: 0;
  transition: .4s;
}

.slider:before {
  background-color: #fff;
  bottom: 0.15em;
  content: "";
  height: 1.2em;
  left: 0.16em;
  position: absolute;
  transition: .4s;
  width: 1.2em;
}

input:checked+.slider {
  background-color: #01BAEF;
}

input:checked+.slider:before {
  transform: translateX(26px);
}

.slider.round {
  border-radius: 34px;
}

.slider.round:before {
  border-radius: 50%;
}

<body>
  <header>
    <div class="nav-container">
      <div class="logo-header">
        <a href="index.html"><img id="mylogo" src="image-of-logo-for darktheme"></a>
      </div>



      <div class="menu-wrap">
        <input type="checkbox" class="toggler">
        <div class="hamburger">
          <div></div>
        </div>
        <div class="menu">
          <div>
            <div>
              <ul>
                <li><a href="about.html">About</a></li>
                <li><a href="projects.html">Projects</a></li>
                <li><a href="experience.html">Experience</a></li>
                <li><a href="education.html">Education</a></li>
                <li><a href="skills.html">Skills</a></li>
                <li><a href="#">Resources</a></li>
                <li><a href="contact.html">Contact</a></li>
                <li>
                  <div class="theme-switch-wrapper">
                    <em><img src="moon-dark"></em>
                    <label class="theme-switch" for="checkbox">
                                            <input type="checkbox" onclick="changeImage()" value="Change" id="checkbox" />
                                            <div class="slider round"></div>
                                        </label>
                    <em><img src="sun-light"></em>
                  </div>
                </li>

              </ul>
            </div>
          </div>
        </div>
      </div>
    </div>
  </header>
  <main>

    <div class="mainpage-container">
      <section class="mainpage-section1">
        <div class="content-image"></div>
      </section>
      <section class="mainpage-section2">
        <div class="mainpage-text">
          <div>
            <h1>I'M A <br>MATERIAL SCIENTIST<br> - PHYSICIST.</h1>
            <h2>(With speciality in nanotechnology, materials science and a Ph.D. in physics.) </h2><br>
            <h2>I develop efficient science communication strategies and create content for science blogs, magazines and, radio/tv shows.</h2>
            <p><a class="contact-link" href="contact.html">Get in touch with me.</a></p>
          </div>
        </div>
      </section>
    </div>

  </main>

</body>

Answer 1

它似乎比它需要的更复杂。您可能会通过添加浅色和深色徽标来找到仅 CSS 的解决方案：

<span id="mylogo">
  <img class="darktheme" src="...">
  <img class="lighttheme" src="...">
</span>

然后相应地设置样式

#mylogo .darktheme,
#mylogo .lighttheme {
 display: none;
}

[data-theme="dark"] #mylogo .darktheme {
  display: inline;
}

[data-theme="light"] #mylogo .lighttheme {
  display: inline;
}

Answer 2

问题 #1

问题是您在用户第一次访问该页面时禁用了这两个徽标，因为默认是深色主题，您应该更改：

#mylogo .darktheme,
#mylogo .lighttheme {
    display: none;
}

进入：

#mylogo .lighttheme {
    display: none;
}

现在应该在用户第一次访问页面时显示深色主题徽标。

问题 #2

在内部存储中将主题设置为浅色时，您没有将图像设置为浅色主题，因此您可以在第 36 行之后插入：

if (currentTheme === 'light') {
    changeImage()
}

因为深色主题标志是默认标志，您只需在主题设置为浅色时切换它。

问题 #1

我在这部分javascript代码中发现了错误：

function changeImage() {
var image = document.getElementById('mylogo');
    if (image.src.match("images/LOGO_SN_over_black.svg")) {
        image.src = "images/LOGO_SN.svg";
    } else {
        image.src = "images/LOGO_SN.svg";
    }
}

如果徽标是深色徽标，则将其更改为正常徽标，如果不是，则再次将其更改为正常徽标，因此，当您切换徽标时，始终放置正常徽标。 要解决这个问题，您需要更改代码，并在徽标不是黑色徽标时将其更改为黑色徽标。比如这样：

function changeImage() {
var image = document.getElementById('mylogo');
    if (image.src.match("images/LOGO_SN_over_black.svg")) {
        image.src = "images/LOGO_SN.svg";
    } else {
        image.src = "images/LOGO_SN_over_black.svg";
    }
}