Question

我有一个简单的导航栏来处理导航栏的粘性缩小。

HTML： -

<!DOCTYPE html>
<html>
<head>
    <title></title>

    <link rel="stylesheet" type="text/css" href="style.css">

    <script type="text/javascript" src="script.js"></script>

    <script src="https://ajax.aspnetcdn.com/ajax/jQuery/jquery-3.2.1.min.js"></script>

    <!-- Latest compiled and minified CSS -->
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">

    <!-- jQuery library -->
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>

    <!-- Latest compiled JavaScript -->
    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
</head>
<body>
    <header></header>

    <nav id="nav" class="nav">
        <div class="nav__inner">
        </div>
    </nav>

    <div class="container">
        <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Incidunt id error ut delectus a sapiente accusantium quam, laudantium, atque laborum, distinctio. Commodi perspiciatis ipsa ducimus labore, iure dignissimos fugit quae.</p>
    </div>

    <footer>This is footer</footer>

</body>
</html>

CSS： -

* {
    box-sizing: border-box;
}

body {
    font-family: 'helvetica neue';
    letter-spacing: 0.03em;
    color: #333;
}

header {
    height: 150px;
    background: black;
}

footer {
    height: 50px;
    background: black;
    color: dodgerblue;
}

.nav {
    position: sticky;
    top: 0;
    height: 80px;
    background: dodgerblue;
    transition: height 200ms ease;

    &.is-shrunk {
        height: 50px;
    }
}

JS： -

const nav = document.getElementById('nav');

const navFromTop = nav.offsetTop;

const navHeight = nav.offsetHeight;

const distanceScrolled = () => {
   return window.pageYOffset;
};

const isScrolledEnough = () => {
   return (distanceScrolled() > navFromTop + navHeight);
};

const setIsShrunk = (value) => {
    if (value && isScrolledEnough()) {
        nav.classList.add('is-shrunk');
    } else if (!value) {
        nav.classList.remove('is-shrunk');
    }
};

window.addEventListener('scroll', () => {
    setIsShrunk(distanceScrolled() > navHeight);
});

我希望此代码在页面滚动时将蓝色导航栏从80px高度缩小到50px高度。

我所做的是从Sticky shrink复制代码。但我没有得到所提到的链接所示的效果。滚动页面时蓝色导航栏没有像链接中那样缩小。可能是什么问题和解决方案。

Answer 1

只需更改：

&.is-shrunk {
        height: 50px;
}

以下内容并将其从CSS中的嵌套.nav选择器中删除。

.nav.is-shrunk {
        height: 50px;
}

＆符号（＆amp;）是一个SASS嵌套选择器，您也可以这样做没有嵌套的操作如下所示。

const nav = document.getElementById('nav');

const navFromTop = nav.offsetTop;

const navHeight = nav.offsetHeight;

const distanceScrolled = () => {
  return window.pageYOffset;
};

const isScrolledEnough = () => {
  return (distanceScrolled() > navFromTop + navHeight);
};

const setIsShrunk = (value) => {
  if (value && isScrolledEnough()) {
    nav.classList.add('is-shrunk');
  } else if (!value) {
    nav.classList.remove('is-shrunk');
  }
};

window.addEventListener('scroll', () => {
  setIsShrunk(distanceScrolled() > navHeight);
});

* {
  box-sizing: border-box;
}

body {
  font-family: 'helvetica neue';
  letter-spacing: 0.03em;
  color: #333;
}

header {
  height: 150px;
  background: black;
}

footer {
  height: 50px;
  background: black;
  color: dodgerblue;
}

.nav {
  position: sticky;
  top: 0;
  height: 80px;
  background: dodgerblue;
  transition: height 200ms ease;
}

.nav.is-shrunk {
  height: 50px;
}

<link rel="stylesheet" type="text/css" href="style.css">

<script type="text/javascript" src="script.js"></script>

<script src="https://ajax.aspnetcdn.com/ajax/jQuery/jquery-3.2.1.min.js"></script>

<!-- Latest compiled and minified CSS -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">

<!-- jQuery library -->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>

<!-- Latest compiled JavaScript -->
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<header></header>

<nav id="nav" class="nav">
  <div class="nav__inner">
  </div>
</nav>

<div class="container">
  <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Incidunt id error ut delectus a sapiente accusantium quam, laudantium, atque laborum, distinctio. Commodi perspiciatis ipsa ducimus labore, iure dignissimos fugit quae.</p>
  <p>Nesciunt eos recusandae adipisci nostrum illum eius. Tempora nemo necessitatibus temporibus quaerat laudantium dolorem minima blanditiis sapiente earum fugiat commodi officiis, magni ducimus corporis, ad! Maiores perspiciatis aperiam quod nemo.</p>
  <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Incidunt id error ut delectus a sapiente accusantium quam, laudantium, atque laborum, distinctio. Commodi perspiciatis ipsa ducimus labore, iure dignissimos fugit quae.</p>
  <p>Nesciunt eos recusandae adipisci nostrum illum eius. Tempora nemo necessitatibus temporibus quaerat laudantium dolorem minima blanditiis sapiente earum fugiat commodi officiis, magni ducimus corporis, ad! Maiores perspiciatis aperiam quod nemo.</p>
  <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Incidunt id error ut delectus a sapiente accusantium quam, laudantium, atque laborum, distinctio. Commodi perspiciatis ipsa ducimus labore, iure dignissimos fugit quae.</p>
  <p>Nesciunt eos recusandae adipisci nostrum illum eius. Tempora nemo necessitatibus temporibus quaerat laudantium dolorem minima blanditiis sapiente earum fugiat commodi officiis, magni ducimus corporis, ad! Maiores perspiciatis aperiam quod nemo.</p>
  <p>Quisquam magni doloribus deserunt rerum, expedita iste numquam ipsum velit beatae, dolores optio sapiente corporis voluptatum mollitia nemo excepturi eveniet provident dolorem facilis incidunt minus aliquam error quas. Distinctio, exercitationem!</p>
  <p>Esse sapiente dolore labore, fuga nobis voluptates explicabo odio asperiores, quod repudiandae totam harum tempora praesentium natus. Blanditiis, sint id sit, ab impedit fuga aliquam distinctio harum, ex molestias voluptates!</p>
  <p>Cumque laborum, ad sequi, reiciendis illum non vero voluptatum libero consequatur quod vitae voluptatem quibusdam incidunt inventore temporibus omnis optio sint quasi soluta. Reprehenderit omnis inventore, doloremque repudiandae minus recusandae.</p>
  <p>Reiciendis hic, placeat laborum iure quo ratione ex perspiciatis, error perferendis sed facilis animi corrupti delectus soluta libero id eligendi iusto magnam itaque. Facere, ducimus. Eveniet officiis quod, vero asperiores.</p>
</div>

<footer>This is footer</footer>

Navbar Sticky Shrink无法正常工作

1 个答案: