[英]How to apply CSS dynamically on child component called twice in parent [Angular]
[英]How to apply normal CSS to an Angular component
我是 Angular 的新手,我正在尝试创建一个带有下拉菜单的导航栏。 我找到了一个相关的代码,它是
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css">
<style>
body {
font-family: Arial, Helvetica, sans-serif;
}
.navbar {
overflow: hidden;
background-color: #333;
}
.navbar a {
float: left;
font-size: 16px;
color: white;
text-align: center;
padding: 14px 16px;
text-decoration: none;
}
.dropdown {
float: left;
overflow: hidden;
}
.dropdown .dropbtn {
font-size: 16px;
border: none;
outline: none;
color: white;
padding: 14px 16px;
background-color: inherit;
font-family: inherit;
margin: 0;
}
.navbar a:hover, .dropdown:hover .dropbtn {
background-color: red;
}
.dropdown-content {
display: none;
position: absolute;
background-color: #f9f9f9;
min-width: 160px;
box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
z-index: 1;
}
.dropdown-content a {
float: none;
color: black;
padding: 12px 16px;
text-decoration: none;
display: block;
text-align: left;
}
.dropdown-content a:hover {
background-color: #ddd;
}
.dropdown:hover .dropdown-content {
display: block;
}
</style>
</head>
<body>
<div class="navbar">
<a href="#home">Home</a>
<a href="#news">News</a>
<div class="dropdown">
<button class="dropbtn">Dropdown
<i class="fa fa-caret-down"></i>
</button>
<div class="dropdown-content">
<a href="#">Link 1</a>
<a href="#">Link 2</a>
<a href="#">Link 3</a>
</div>
</div>
</div>
<h3>Dropdown Menu inside a Navigation Bar</h3>
<p>Hover over the "Dropdown" link to see the dropdown menu.</p>
</body>
</html>
在单个 html 文件中运行时,它工作正常。
但我想把它放在我的 Angular 项目中。所以我创建了一个单独的组件作为 header 并将 html 部分放在“header.component.html 文件”中
<a href="#home">Home</a> <a href="#news">News</a> <div class="dropdown"> <button class="dropbtn">Dropdown <i class="fa fa-caret-down"></i> </button> <div class="dropdown-content"> <a href="#">Link 1</a> <a href="#">Link 2</a> <a href="#">Link 3</a> </div> </div> </div>
并将 css 部分放入“header.component.css”文件中
body {
font-family: Arial, Helvetica, sans-serif;
}
.navbar {
overflow: hidden;
background-color: #333;
}
.navbar a {
float: left;
font-size: 16px;
color: white;
text-align: center;
padding: 14px 16px;
text-decoration: none;
}
.dropdown {
float: left;
overflow: hidden;
}
.dropdown .dropbtn {
font-size: 16px;
border: none;
outline: none;
color: white;
padding: 14px 16px;
background-color: inherit;
font-family: inherit;
margin: 0;
}
.navbar a:hover, .dropdown:hover .dropbtn {
background-color: red;
}
.dropdown-content {
display: none;
position: absolute;
background-color: #f9f9f9;
min-width: 160px;
box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
z-index: 1;
}
.dropdown-content a {
float: none;
color: black;
padding: 12px 16px;
text-decoration: none;
display: block;
text-align: left;
}
.dropdown-content a:hover {
background-color: #ddd;
}
.dropdown:hover .dropdown-content {
display: block;
}
但问题是,尽管按预期应用了一些 styles,但下拉不起作用。
.dropdown:hover .dropdown-content {
display: block;
}
可能不适用于 html 文件。所以请帮助我。我想知道我应用 css 的方式是否正确。如果不正确,请告诉我正确的做法。
Since angular uses ViewEncapsulation.Emulated
as default, the styles inside header.component.css
are only applied to elements inside header.component.html
. 由于您的body
和.navbar
元素不在header.component.html
内,因此不应用 styles。 将这些 styles 移动到正确的组件样式表中或将它们移动到由 angular 创建的全局样式表中。 要测试您的问题是否与ViewEncapsulation.Emulated
相关,您可以使用ViewEncapsulation.None
ViewEncapsulation
将整个 CSS 移动到全局样式表。
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