CSS 预加载器不会转换为文本

Question

我正在关注 this tutorial 并设法创建了一个 css 预加载器。

但是，预加载器将无法正常工作。它显示加载程序，位工作正常，但不会转换为文本位。我不知道我做错了什么。我按照教程进行操作，甚至将 CSS/JS 代码复制到我自己的脚本中以确认它不起作用。还是不行。

你能看一下代码并告诉我我做错了什么吗？谢谢

PS: 所有这些文件都位于同一目录中。

$(document).ready(function() {

  setTimeout(function() {
    $('body').addClass('loaded');
    $('h1').css('color', '#222222');
  }, 3000);

});

p {
  line-height: 1.33em;
  color: #7E7E7E;
}
h1 {
  color: #EEEEEE;
}
#loader-wrapper {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 1000;
}
#loader {
  display: block;
  position: relative;
  left: 50%;
  top: 50%;
  width: 150px;
  height: 150px;
  margin: -75px 0 0 -75px;
  border-radius: 50%;
  border: 3px solid transparent;
  border-top-color: #3498db;
  -webkit-animation: spin 2s linear infinite;
  /* Chrome, Opera 15+, Safari 5+ */
  animation: spin 2s linear infinite;
  /* Chrome, Firefox 16+, IE 10+, Opera */
  z-index: 1001;
}
#loader:before {
  content: "";
  position: absolute;
  top: 5px;
  left: 5px;
  right: 5px;
  bottom: 5px;
  border-radius: 50%;
  border: 3px solid transparent;
  border-top-color: #e74c3c;
  -webkit-animation: spin 3s linear infinite;
  /* Chrome, Opera 15+, Safari 5+ */
  animation: spin 3s linear infinite;
  /* Chrome, Firefox 16+, IE 10+, Opera */
}
#loader:after {
  content: "";
  position: absolute;
  top: 15px;
  left: 15px;
  right: 15px;
  bottom: 15px;
  border-radius: 50%;
  border: 3px solid transparent;
  border-top-color: #f9c922;
  -webkit-animation: spin 1.5s linear infinite;
  /* Chrome, Opera 15+, Safari 5+ */
  animation: spin 1.5s linear infinite;
  /* Chrome, Firefox 16+, IE 10+, Opera */
}
@-webkit-keyframes spin {
  0% {
    -webkit-transform: rotate(0deg);
    /* Chrome, Opera 15+, Safari 3.1+ */
    -ms-transform: rotate(0deg);
    /* IE 9 */
    transform: rotate(0deg);
    /* Firefox 16+, IE 10+, Opera */
  }
  100% {
    -webkit-transform: rotate(360deg);
    /* Chrome, Opera 15+, Safari 3.1+ */
    -ms-transform: rotate(360deg);
    /* IE 9 */
    transform: rotate(360deg);
    /* Firefox 16+, IE 10+, Opera */
  }
}
@keyframes spin {
  0% {
    -webkit-transform: rotate(0deg);
    /* Chrome, Opera 15+, Safari 3.1+ */
    -ms-transform: rotate(0deg);
    /* IE 9 */
    transform: rotate(0deg);
    /* Firefox 16+, IE 10+, Opera */
  }
  100% {
    -webkit-transform: rotate(360deg);
    /* Chrome, Opera 15+, Safari 3.1+ */
    -ms-transform: rotate(360deg);
    /* IE 9 */
    transform: rotate(360deg);
    /* Firefox 16+, IE 10+, Opera */
  }
}
#loader-wrapper .loader-section {
  position: fixed;
  top: 0;
  width: 51%;
  height: 100%;
  background: #222222;
  z-index: 1000;
  -webkit-transform: translateX(0);
  /* Chrome, Opera 15+, Safari 3.1+ */
  -ms-transform: translateX(0);
  /* IE 9 */
  transform: translateX(0);
  /* Firefox 16+, IE 10+, Opera */
}
#loader-wrapper .loader-section.section-left {
  left: 0;
}
#loader-wrapper .loader-section.section-right {
  right: 0;
}
/* Loaded */

.loaded #loader-wrapper .loader-section.section-left {
  -webkit-transform: translateX(-100%);
  /* Chrome, Opera 15+, Safari 3.1+ */
  -ms-transform: translateX(-100%);
  /* IE 9 */
  transform: translateX(-100%);
  /* Firefox 16+, IE 10+, Opera */
  -webkit-transition: all 0.7s 0.3s cubic-bezier(0.645, 0.045, 0.355, 1.000);
  transition: all 0.7s 0.3s cubic-bezier(0.645, 0.045, 0.355, 1.000);
}
.loaded #loader-wrapper .loader-section.section-right {
  -webkit-transform: translateX(100%);
  /* Chrome, Opera 15+, Safari 3.1+ */
  -ms-transform: translateX(100%);
  /* IE 9 */
  transform: translateX(100%);
  /* Firefox 16+, IE 10+, Opera */
  -webkit-transition: all 0.7s 0.3s cubic-bezier(0.645, 0.045, 0.355, 1.000);
  transition: all 0.7s 0.3s cubic-bezier(0.645, 0.045, 0.355, 1.000);
}
.loaded #loader {
  opacity: 0;
  -webkit-transition: all 0.3s ease-out;
  transition: all 0.3s ease-out;
}
.loaded #loader-wrapper {
  visibility: hidden;
  -webkit-transform: translateY(-100%);
  /* Chrome, Opera 15+, Safari 3.1+ */
  -ms-transform: translateY(-100%);
  /* IE 9 */
  transform: translateY(-100%);
  /* Firefox 16+, IE 10+, Opera */
  -webkit-transition: all 0.3s 1s ease-out;
  transition: all 0.3s 1s ease-out;
}
/* JavaScript Turned Off */

.no-js #loader-wrapper {
  display: none;
}
.no-js h1 {
  color: #222222;
}
#content {
  margin: 0 auto;
  padding-bottom: 50px;
  width: 80%;
  max-width: 978px;
}

<!DOCTYPE html>

<html>

<head>
  <link rel="stylesheet" href="./preloader.css">
</head>

<body>
  <div id="loader-wrapper">
    <div id="loader"></div>

    <div class="loader-section section-left"></div>
    <div class="loader-section section-right"></div>

    <div id="content">
      <h2>This is our page title</h2>
      <p>Lorem ipsum dolor sit amet.</p>
    </div>
  </div>
  <script src="./preloader.js"></script>
</body>

</html>

Answer 1

问题是在你的 js 中，你正在使用 jquery 中的选择器和方法，例如 $、.addClass、.css，要使用它，你必须包含 jQuery

https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js

看看这个http://www.w3schools.com/jquery/jquery_selectors.asp

或者你可以像这样用纯 javascript 来做：

document.addEventListener("DOMContentLoaded", function(event) { 
  setTimeout(function() {
    document.querySelector("body").className = "loaded"; 
    document.querySelector("h1").style.color = "#222222";
  }, 3000);

});

p {
  line-height: 1.33em;
  color: #7E7E7E;
}
h1 {
  color: #EEEEEE;
}
#loader-wrapper {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 1000;
}
#loader {
  display: block;
  position: relative;
  left: 50%;
  top: 50%;
  width: 150px;
  height: 150px;
  margin: -75px 0 0 -75px;
  border-radius: 50%;
  border: 3px solid transparent;
  border-top-color: #3498db;
  -webkit-animation: spin 2s linear infinite;
  /* Chrome, Opera 15+, Safari 5+ */
  animation: spin 2s linear infinite;
  /* Chrome, Firefox 16+, IE 10+, Opera */
  z-index: 1001;
}
#loader:before {
  content: "";
  position: absolute;
  top: 5px;
  left: 5px;
  right: 5px;
  bottom: 5px;
  border-radius: 50%;
  border: 3px solid transparent;
  border-top-color: #e74c3c;
  -webkit-animation: spin 3s linear infinite;
  /* Chrome, Opera 15+, Safari 5+ */
  animation: spin 3s linear infinite;
  /* Chrome, Firefox 16+, IE 10+, Opera */
}
#loader:after {
  content: "";
  position: absolute;
  top: 15px;
  left: 15px;
  right: 15px;
  bottom: 15px;
  border-radius: 50%;
  border: 3px solid transparent;
  border-top-color: #f9c922;
  -webkit-animation: spin 1.5s linear infinite;
  /* Chrome, Opera 15+, Safari 5+ */
  animation: spin 1.5s linear infinite;
  /* Chrome, Firefox 16+, IE 10+, Opera */
}
@-webkit-keyframes spin {
  0% {
    -webkit-transform: rotate(0deg);
    /* Chrome, Opera 15+, Safari 3.1+ */
    -ms-transform: rotate(0deg);
    /* IE 9 */
    transform: rotate(0deg);
    /* Firefox 16+, IE 10+, Opera */
  }
  100% {
    -webkit-transform: rotate(360deg);
    /* Chrome, Opera 15+, Safari 3.1+ */
    -ms-transform: rotate(360deg);
    /* IE 9 */
    transform: rotate(360deg);
    /* Firefox 16+, IE 10+, Opera */
  }
}
@keyframes spin {
  0% {
    -webkit-transform: rotate(0deg);
    /* Chrome, Opera 15+, Safari 3.1+ */
    -ms-transform: rotate(0deg);
    /* IE 9 */
    transform: rotate(0deg);
    /* Firefox 16+, IE 10+, Opera */
  }
  100% {
    -webkit-transform: rotate(360deg);
    /* Chrome, Opera 15+, Safari 3.1+ */
    -ms-transform: rotate(360deg);
    /* IE 9 */
    transform: rotate(360deg);
    /* Firefox 16+, IE 10+, Opera */
  }
}
#loader-wrapper .loader-section {
  position: fixed;
  top: 0;
  width: 51%;
  height: 100%;
  background: #222222;
  z-index: 1000;
  -webkit-transform: translateX(0);
  /* Chrome, Opera 15+, Safari 3.1+ */
  -ms-transform: translateX(0);
  /* IE 9 */
  transform: translateX(0);
  /* Firefox 16+, IE 10+, Opera */
}
#loader-wrapper .loader-section.section-left {
  left: 0;
}
#loader-wrapper .loader-section.section-right {
  right: 0;
}
/* Loaded */

.loaded #loader-wrapper .loader-section.section-left {
  -webkit-transform: translateX(-100%);
  /* Chrome, Opera 15+, Safari 3.1+ */
  -ms-transform: translateX(-100%);
  /* IE 9 */
  transform: translateX(-100%);
  /* Firefox 16+, IE 10+, Opera */
  -webkit-transition: all 0.7s 0.3s cubic-bezier(0.645, 0.045, 0.355, 1.000);
  transition: all 0.7s 0.3s cubic-bezier(0.645, 0.045, 0.355, 1.000);
}
.loaded #loader-wrapper .loader-section.section-right {
  -webkit-transform: translateX(100%);
  /* Chrome, Opera 15+, Safari 3.1+ */
  -ms-transform: translateX(100%);
  /* IE 9 */
  transform: translateX(100%);
  /* Firefox 16+, IE 10+, Opera */
  -webkit-transition: all 0.7s 0.3s cubic-bezier(0.645, 0.045, 0.355, 1.000);
  transition: all 0.7s 0.3s cubic-bezier(0.645, 0.045, 0.355, 1.000);
}
.loaded #loader {
  opacity: 0;
  -webkit-transition: all 0.3s ease-out;
  transition: all 0.3s ease-out;
}
.loaded #loader-wrapper {
  visibility: hidden;
  -webkit-transform: translateY(-100%);
  /* Chrome, Opera 15+, Safari 3.1+ */
  -ms-transform: translateY(-100%);
  /* IE 9 */
  transform: translateY(-100%);
  /* Firefox 16+, IE 10+, Opera */
  -webkit-transition: all 0.3s 1s ease-out;
  transition: all 0.3s 1s ease-out;
}
/* JavaScript Turned Off */

.no-js #loader-wrapper {
  display: none;
}
.no-js h1 {
  color: #222222;
}
#content {
  margin: 0 auto;
  padding-bottom: 50px;
  width: 80%;
  max-width: 978px;
}

<!DOCTYPE html>

<html>

<head>
  <link rel="stylesheet" href="./preloader.css">
</head>

<body>
  <div id="loader-wrapper">
    <div id="loader"></div>

    <div class="loader-section section-left"></div>
    <div class="loader-section section-right"></div>

    <div id="content">
      <h2>This is our page title</h2>
      <p>Lorem ipsum dolor sit amet.</p>
    </div>
  </div>
  <script src="./preloader.js"></script>
</body>

</html>

我真的建议您添加 jquery 并避免您必须使用纯 javascript 来做所有事情。

Answer 2

包含后jQuery

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js">

以上

<script src="./preloader.js"></script>

您可以阅读 About jQuery、为什么需要 jQuery 以及 jQuery 脚本如何工作，以便您可以自己调试这些小问题

工作示例（不需要更改任何其他内容）

$(document).ready(function() {

  setTimeout(function() {
    $('body').addClass('loaded');
    $('h1').css('color', '#222222');
  }, 3000);

});

p {
  line-height: 1.33em;
  color: #7E7E7E;
}
h1 {
  color: #EEEEEE;
}
#loader-wrapper {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 1000;
}
#loader {
  display: block;
  position: relative;
  left: 50%;
  top: 50%;
  width: 150px;
  height: 150px;
  margin: -75px 0 0 -75px;
  border-radius: 50%;
  border: 3px solid transparent;
  border-top-color: #3498db;
  -webkit-animation: spin 2s linear infinite;
  /* Chrome, Opera 15+, Safari 5+ */
  animation: spin 2s linear infinite;
  /* Chrome, Firefox 16+, IE 10+, Opera */
  z-index: 1001;
}
#loader:before {
  content: "";
  position: absolute;
  top: 5px;
  left: 5px;
  right: 5px;
  bottom: 5px;
  border-radius: 50%;
  border: 3px solid transparent;
  border-top-color: #e74c3c;
  -webkit-animation: spin 3s linear infinite;
  /* Chrome, Opera 15+, Safari 5+ */
  animation: spin 3s linear infinite;
  /* Chrome, Firefox 16+, IE 10+, Opera */
}
#loader:after {
  content: "";
  position: absolute;
  top: 15px;
  left: 15px;
  right: 15px;
  bottom: 15px;
  border-radius: 50%;
  border: 3px solid transparent;
  border-top-color: #f9c922;
  -webkit-animation: spin 1.5s linear infinite;
  /* Chrome, Opera 15+, Safari 5+ */
  animation: spin 1.5s linear infinite;
  /* Chrome, Firefox 16+, IE 10+, Opera */
}
@-webkit-keyframes spin {
  0% {
    -webkit-transform: rotate(0deg);
    /* Chrome, Opera 15+, Safari 3.1+ */
    -ms-transform: rotate(0deg);
    /* IE 9 */
    transform: rotate(0deg);
    /* Firefox 16+, IE 10+, Opera */
  }
  100% {
    -webkit-transform: rotate(360deg);
    /* Chrome, Opera 15+, Safari 3.1+ */
    -ms-transform: rotate(360deg);
    /* IE 9 */
    transform: rotate(360deg);
    /* Firefox 16+, IE 10+, Opera */
  }
}
@keyframes spin {
  0% {
    -webkit-transform: rotate(0deg);
    /* Chrome, Opera 15+, Safari 3.1+ */
    -ms-transform: rotate(0deg);
    /* IE 9 */
    transform: rotate(0deg);
    /* Firefox 16+, IE 10+, Opera */
  }
  100% {
    -webkit-transform: rotate(360deg);
    /* Chrome, Opera 15+, Safari 3.1+ */
    -ms-transform: rotate(360deg);
    /* IE 9 */
    transform: rotate(360deg);
    /* Firefox 16+, IE 10+, Opera */
  }
}
#loader-wrapper .loader-section {
  position: fixed;
  top: 0;
  width: 51%;
  height: 100%;
  background: #222222;
  z-index: 1000;
  -webkit-transform: translateX(0);
  /* Chrome, Opera 15+, Safari 3.1+ */
  -ms-transform: translateX(0);
  /* IE 9 */
  transform: translateX(0);
  /* Firefox 16+, IE 10+, Opera */
}
#loader-wrapper .loader-section.section-left {
  left: 0;
}
#loader-wrapper .loader-section.section-right {
  right: 0;
}
/* Loaded */

.loaded #loader-wrapper .loader-section.section-left {
  -webkit-transform: translateX(-100%);
  /* Chrome, Opera 15+, Safari 3.1+ */
  -ms-transform: translateX(-100%);
  /* IE 9 */
  transform: translateX(-100%);
  /* Firefox 16+, IE 10+, Opera */
  -webkit-transition: all 0.7s 0.3s cubic-bezier(0.645, 0.045, 0.355, 1.000);
  transition: all 0.7s 0.3s cubic-bezier(0.645, 0.045, 0.355, 1.000);
}
.loaded #loader-wrapper .loader-section.section-right {
  -webkit-transform: translateX(100%);
  /* Chrome, Opera 15+, Safari 3.1+ */
  -ms-transform: translateX(100%);
  /* IE 9 */
  transform: translateX(100%);
  /* Firefox 16+, IE 10+, Opera */
  -webkit-transition: all 0.7s 0.3s cubic-bezier(0.645, 0.045, 0.355, 1.000);
  transition: all 0.7s 0.3s cubic-bezier(0.645, 0.045, 0.355, 1.000);
}
.loaded #loader {
  opacity: 0;
  -webkit-transition: all 0.3s ease-out;
  transition: all 0.3s ease-out;
}
.loaded #loader-wrapper {
  visibility: hidden;
  -webkit-transform: translateY(-100%);
  /* Chrome, Opera 15+, Safari 3.1+ */
  -ms-transform: translateY(-100%);
  /* IE 9 */
  transform: translateY(-100%);
  /* Firefox 16+, IE 10+, Opera */
  -webkit-transition: all 0.3s 1s ease-out;
  transition: all 0.3s 1s ease-out;
}
/* JavaScript Turned Off */

.no-js #loader-wrapper {
  display: none;
}
.no-js h1 {
  color: #222222;
}
#content {
  margin: 0 auto;
  padding-bottom: 50px;
  width: 80%;
  max-width: 978px;
}

<!DOCTYPE html>

<html>

<head>
  <link rel="stylesheet" href="./preloader.css">
</head>

<body>
  <div id="loader-wrapper">
    <div id="loader"></div>

    <div class="loader-section section-left"></div>
    <div class="loader-section section-right"></div>

    <div id="content">
      <h2>This is our page title</h2>
      <p>Lorem ipsum dolor sit amet.</p>
    </div>
  </div>
  <script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
  <script src="./preloader.js"></script>
</body>

</html>

CSS 预加载器不会转换为文本

CSS Preloader won't transition to text

html

javascript

css

jquery

preloader