当我将手机的方向更改为横向，然后再次更改为纵向，然后是“欢迎学生!”的字体大小更改而不是在两行中显示它，浏览器将它显示在一行中，字体较小。我使用 Bootstrap “display-1”表示“欢迎”，使用“display-3”表示“学生!”。我缩短了字体大小返回原始方向后发生变化。
/* and if you want script also then */
function css_ruling() {
var winw = window.innerWidth
var winh = window.innerHeight
var heading = document.getElementById("name")
var first_look = document.getElementById("first")
first_look.style.height = ((0.95) * winh) + "px";
first_look.style.width = winw + "px";
}
setInterval(() => {
css_ruling()
}, 5);html {
-webkit-text-size-adjust: none;
}
#first {
background-image: linear-gradient(141deg, #9fb8ad 0%, #1fc8db 51%, #2cb5e8 75%);
}
#name {
text-align: center;
color: white;
font-family: 'Quicksand';
}
.banner-img {
background-image: url("../resources/banner.jpg");
background-attachment: fixed;
background-size: 100% 100%;
width: 100%;
height: 980px;
}
.avtar {
width: 10%;
min-width: 150px;
}<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
<link rel="stylesheet" href="bootstrap/bootstrap.min.css?v=2">
<link rel="stylesheet" href="css/style.css?v=4">
<link href="https://fonts.googleapis.com/css?family=Quicksand:300,500" rel="stylesheet">
</head>
<body>
<section id="first">
<div id="nav">
<nav class="navbar navbar-expand-lg navbar-dark ">
<a class="navbar-brand" href="#">Homework.com</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarColor01" aria-controls="navbarColor01" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse text-center" id="navbarColor01">
<ul class="navbar-nav mr-auto">
<li class="nav-item active">
<a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Features</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Pricing</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">About</a>
</li>
</ul>
<form class="form-inline">
<input class="form-control mr-sm-2" type="search" placeholder="Search" aria-label="Search">
<button class="btn btn-outline-info text-white my-2 my-sm-0 ml-auto mr-auto" type="submit">Search</button>
</form>
</div>
</nav>
</div>
<div id="name" class="pt-5"><span class="display-1">Welcome </span><span class="display-3">Students!</span></div>
<div id="form_login">
<form action="" class="">
<div class="text-center pt-5">
<img src="resources/man.svg" style="min-width: 90px" class="avtar" alt="">
</div>
</form>
</div>
</section>
<!-- <script src="bootstrap/bootstrap.min.js"></script> -->
<!-- <script src="bootstrap/jquery-3.3.1.slim.min.js"></script> -->
<!-- <script src="bootstrap/popper.min.js"></script> -->
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js" integrity="sha384-UO2eT0CpHqdSJQ6hJty5KVphtPhzWj9WO1clHTMGa3JDZwrnQq4sF86dIHNDz0W1" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js" integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM" crossorigin="anonymous"></script>
<script src="js/script.js?v=2"></script>
</body>
</html>最佳答案
尝试使用原生 API，
@media (orientation: landscape) {
//styles
}
@media (orientation: portrait) {
//styles
}
使用 setInterval 方法计算设备高度和宽度不太可能给您想要的结果。 https://developer.mozilla.org/en-US/docs/Web/Performance/Critical_rendering_path
关于html - 在基于 Bootstrap 的网站中更改方向后字体大小发生变化，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/58109107/