在使用Bootstrap 3的固定顶部导航时，我注意到当用户在移动设备上使用原生缩放时，顶部导航也变得非常大。这会导致非常糟糕的用户体验，导航模糊了大部分内容并最终自行损坏，如以下示例所示：
这个问题可以在网上看到http://www.exploretrade.info/ http://www.exploretrade.info/并且似乎也影响了许多其他使用这种导航的网站；常见的解决方案是禁用用户缩放，但这会损害网站的可访问性。
我的问题是：当用户在移动设备上缩放内容时，如何保持固定顶部导航的显示大小不变
transform: scale指示2 https://signalvnoise.com/posts/2407-device-scale-user-interface-elements-in-ios-mobile-safari
position: fixed元素，缩小后最终以某种方式居中于屏幕navbar-top-fixed通过手机缩放 The final result:
仅在移动设备上，可以将缩放系数计算为window.innerWidth和屏幕宽度，如[2]所示。当用户切换缩放时，会触发调整大小事件；此外，当重新加载先前缩放的页面时，缩放系数将保持不变。因此，可以使用 jQuery 动态更新 CSS 转换，以保持标题的形状。请注意，与position: fixed，还需要对原点进行变换。申请班级device-fixed-height到引导程序nav and device-fixed-width品牌徽标和汉堡图标然后产生非常接近所需的结果。
实例: http://www.exploretrade.info/other/example-fixed-nav-after-zoom.html http://www.exploretrade.info/other/example-fixed-nav-after-zoom.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1">
<meta name="description" content="">
<meta name="author" content="">
<link rel="icon" href="../../favicon.ico">
<title>Bootstrap zoom-proof fixed top nav</title>
<!-- Bootstrap core CSS -->
<link href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.1/css/bootstrap.min.css" rel="stylesheet">
<!-- Custom styles for this template -->
<link href="//maxcdn.bootstrapcdn.com/font-awesome/4.2.0/css/font-awesome.min.css" rel="stylesheet">
<style>
body {
padding-top: 50px;
}
</style>
</head>
<body>
<nav class="navbar navbar-inverse navbar-fixed-top device-fixed-height">
<div class="container">
<div class="navbar-header">
<button type="button" class="navbar-toggle collapsed device-fixed-width" data-toggle="collapse" data-target="#navbar" aria-expanded="false" aria-controls="navbar">
<span class="sr-only">Toggle navigation</span>
<i class="fa fa-bars"></i>
</button>
<a class="navbar-brand device-fixed-width" href="#">Example</a>
</div>
<div id="navbar" class="collapse navbar-collapse device-fixed-width">
<ul class="nav navbar-nav">
<li class="active"><a href="#">Home</a></li>
<li><a href="#about">About</a></li>
<li><a href="#contact">Contact</a></li>
</ul>
</div><!--/.nav-collapse -->
</div>
</nav>
<div class="container">
<div class="starter-template">
<h1>Bootstrap starter template</h1>
<p class="lead">Use this document as a way to quickly start any new project.<br> All you get is this text and a mostly barebones HTML document.</p>
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. In in metus eget nisi imperdiet dictum ac eu metus. Morbi consequat sodales porta. Nam convallis sed dolor in ullamcorper. Vestibulum ut tortor porttitor, venenatis nulla iaculis, sollicitudin metus. Mauris ut hendrerit purus, sed ultricies lacus. Proin imperdiet, lectus vel efficitur hendrerit, quam tortor efficitur sapien, vehicula viverra magna ipsum vitae lacus. Sed faucibus elit vel massa placerat, in porttitor est suscipit. Pellentesque consequat condimentum elit, at sagittis erat euismod nec. Fusce consequat purus quis turpis volutpat, vel luctus tortor consectetur. Sed in lectus vitae enim fringilla faucibus. Mauris vitae risus ut ex convallis luctus. Interdum et malesuada fames ac ante ipsum primis in faucibus. Etiam tempor ante augue, sed iaculis nisi porta quis.</p>
</div>
</div><!-- /.container -->
<!-- Bootstrap core JavaScript
================================================== -->
<!-- Placed at the end of the document so the pages load faster -->
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<script src="//maxcdn.bootstrapcdn.com/bootstrap/3.3.1/js/bootstrap.min.js"></script>
<script>
// from https://signalvnoise.com/posts/2407-device-scale-user-interface-elements-in-ios-mobile-safari
function getDeviceScale() {
var deviceWidth, landscape = Math.abs(window.orientation) == 90;
if (landscape) {
// iPhone OS < 3.2 reports a screen height of 396px
deviceWidth = Math.max(480, screen.height);
} else {
deviceWidth = screen.width;
}
return window.innerWidth / deviceWidth;
}
// mobile only - keep the position:fixed header at constant size when page is zoomed
if (navigator.userAgent.match(/Mobi/)) {
$(window).on('load scroll', function() {
var ds = getDeviceScale();
$('.device-fixed-height').css('transform','scale(1,' + ds + ')')
.css('transform-origin', '0 0');
$('.device-fixed-width').css('transform', 'scale(' + ds + ',1)')
.css('transform-origin', '0 0');
})
}
</script>
</script>
</body>
</html>