当滚动到顶部文档时,我尝试使用我的代码制作透明导航栏(opacity = 0),并在滚动传递对象时设置为 opacity = 1。但似乎代码对我不起作用。有人可以从 jsFiddle 查看我的代码并解决这个问题吗? Fiddle
$(document).on('scroll', function (e) {
var o = $(document).scrollTop() / 500;
if (o > 1.000) { o = 1;}
var e = $('nav');
var currentColor = $('nav').css('background-color');
var lastComma = currentColor.lastIndexOf(')');
var newColor = currentColor.slice(0, lastComma - 1) + ", "+ o + ")";
$('nav').css('background-color', newColor);
});
最佳答案
三件事:
materialize.min.css
应用background-color
!important
标志。自!important
flag can override inline styles , 你 在应用时将需要另一个!important
标志来覆盖它 内联样式。我知道很乱,但我想不出任何其他方式。- 您正在从元素中提取
rgb
(不带 alpha)值,但您想将rgba
(带 alpha)应用于它。您得到的newColor
变量将需要适应这一点。 - 最后,通过
.css()
应用在这里无济于事。我们需要使用.attr()
直接应用于style
属性并以字符串格式将所有内容连接在一起。
以下是我认为您可以做的事情:
$(document).on('scroll', function (e) { updateColor(); });
function updateColor() {
var o = $(document).scrollTop() / 500;
if (o > 1.000) { o = 1; }
var e = $('nav');
var currentColor = e.css('background-color');
var rgb = currentColor.replace(/^(rgb|rgba)\(/, '').replace(/\)$/, '').replace(/\s/g, '').split(',');
var newColor = 'rgba(' + rgb[0] + ',' + rgb[1] + ',' + rgb[2] + ',' + o + ')';
e.attr('style', 'background-color: ' + newColor + ' !important');
}
updateColor();
片段:
$(document).on('scroll', function (e) { updateColor(); });
function updateColor() {
var o = $(document).scrollTop() / 500;
if (o > 1.000) { o = 1; }
var e = $('nav');
var currentColor = e.css('background-color');
var rgb = currentColor.replace(/^(rgb|rgba)\(/, '').replace(/\)$/, '').replace(/\s/g, '').split(',');
var newColor = 'rgba(' + rgb[0] + ',' + rgb[1] + ',' + rgb[2] + ',' + o + ')';
e.attr('style', 'background-color: ' + newColor + ' !important');
}
updateColor();
header, main, footer { padding-left: 0px; }
a.button-collapse { padding-left: 15px; }
a.brand-logo.left-align.hide-on-med-and-down { padding-left: 20px; }
a.brand-logo.left-align.hide-on-small-only.hide-on-large-only { font-size: 1.675rem; }
a.brand-logo.left-align.hide-on-small-only.hide-on-large-only span { font-size: 1.12rem; }
@media only screen and (max-width: 320px) {
a.brand-logo.left-align.hide-on-med-and-up { font-size: 1.15rem; }
}
@media only screen and (min-width: 321px) {
a.brand-logo.left-align.hide-on-med-and-up { font-size: 1.25rem; }
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<link href="https://cdnjs.cloudflare.com/ajax/libs/materialize/0.96.1/css/materialize.min.css" rel="stylesheet"/>
<script src="https://cdnjs.cloudflare.com/ajax/libs/materialize/0.96.1/js/materialize.min.js"></script>
<script src="http://materializecss.com/js/init.js"></script>
<header>
<div class="navbar-fixed" id="top">
<nav class="orange"> <a href="#" data-activates="mobile-demo" class="button-collapse"><i class="mdi-navigation-menu"></i></a>
<a class="brand-logo left-align">Header</a>
<ul class="right hide-on-med-and-down">
<li><a class="waves-effect waves-light" id="test">Item 1</a></li>
<li><a class="waves-effect waves-light">Item 2</a></li>
<li><a class="waves-effect waves-light">Item 3</a></li>
<li><a class="waves-effect waves-light">Item 4</a></li>
</ul>
<ul class="side-nav left-align" id="mobile-demo">
<li class="waves-effect waves-red" style="width: 100%;"><a>Item 1</a></li>
<li class="waves-effect waves-red" style="width: 100%;"><a>Item 2</a></li>
<li class="waves-effect waves-red" style="width: 100%;"><a>Item 3</a></li>
<li class="waves-effect waves-red" style="width: 100%;"><a>Item 4</a></li>
</ul>
</nav>
</div>
</header>
<main style="margin-top: -64px;">
<div style="width: 100%; height: 100vh; min-height:480px; background-color: #ccc; font-size: 3rem; vertical-align: center;">
<div class="valign-wrapper center-align" style="margin-top: 65px;">
<div class="valign">Transparent Navbar Section</div>
<div class="valign grey-text text-darken-" 2 style="">(Opacity = 0%)</div>
</div>
</div>
<p class="navopc-endchange"><u>End Color Opacity Change!(Opacity = 100%)</u></p>
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希望这对您有所帮助。
关于javascript - 滚动到文档顶部时如何制作透明导航栏,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/31751392/