Javascript 带有居中徽标的自定义引导导航栏
我正试图用一个居中的标志和阴影效果来重现这一点 我已经设法让JS效果在图像在滚动时收缩的地方工作 我已经走了这么远,但我如何定位图像,使其位于导航的中心 另外,如何在导航栏和图像下创建阴影 HTML JSJavascript 带有居中徽标的自定义引导导航栏,javascript,html,css,bootstrap-4,Javascript,Html,Css,Bootstrap 4,我正试图用一个居中的标志和阴影效果来重现这一点 我已经设法让JS效果在图像在滚动时收缩的地方工作 我已经走了这么远,但我如何定位图像,使其位于导航的中心 另外,如何在导航栏和图像下创建阴影 HTML JS window.onscroll=function(){ growshrinkogo() }; var Logo=document.getElementById(“Logo”); var endOfDocumentTop=150; 变量大小=0; 函数growshrinkogo(){ var s
window.onscroll=function(){
growshrinkogo()
};
var Logo=document.getElementById(“Logo”);
var endOfDocumentTop=150;
变量大小=0;
函数growshrinkogo(){
var scroll=window.pageYOffset | | | document.documentElement.scrollTop | | | document.body.scrollTop | | 0;
如果(大小==0&&scroll>endOfDocumentTop){
Logo.className='smallLogo';
尺寸=1;
}否则,如果(大小==1&&scroll您需要添加右:0;左:0;边距:0自动;
以将图像对齐到中心位置。此外,使用框阴影
属性为导航栏和图像添加阴影
window.onscroll=function(){
growshrinkogo()
};
var Logo=document.getElementById(“Logo”);
var endOfDocumentTop=150;
变量大小=0;
函数growshrinkogo(){
var scroll=window.pageYOffset | | | document.documentElement.scrollTop | | | document.body.scrollTop | | 0;
如果(大小==0&&scroll>endOfDocumentTop){
Logo.className='smallLogo';
尺寸=1;
}else if(size==1&&滚动阴影:水平中心:谢谢毗湿奴-看起来很棒!很高兴帮助..编码愉快!
<nav class="navbar navbar-expand-lg sticky-top navbar-light bg-light
flex-column">
<div class="container">
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav" aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="navbar-collapse collapse" id="navbarNav">
<ul class="navbar-nav nav-fill w-100">
<li class="nav-item active align-self-center">
<a class="nav-link" href="#">About<span class="sr-only">(current)</span></a>
</li>
<li class="nav-item align-self-center">
<a class="nav-link" href="#">Books</a>
</li>
<li class="nav-item">
<a class="navbar-brand mx-auto" href="index.html"> <img src="https://placeimg.com/640/480/any" class="largeLogo" id="Logo" alt="Star Books"></a>
</li>
<li class="nav-item align-self-center">
<a class="nav-link" href="#">Book Club</a>
</li>
<li class="nav-item align-self-center">
<a class="nav-link" href="#">Contact</a>
</li>
</ul>
</div>
</div>
</nav>
#Logo {
position: absolute;
transition: all 0.5s;
border-radius: 50%;
}
.largeLogo {
width: 200px;
}
.smallLogo {
width: 100px;
}
window.onscroll = function() {
growShrinkLogo()
};
var Logo = document.getElementById("Logo");
var endOfDocumentTop = 150;
var size = 0;
function growShrinkLogo() {
var scroll = window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop || 0;
if (size == 0 && scroll > endOfDocumentTop) {
Logo.className = 'smallLogo';
size = 1;
} else if (size == 1 && scroll <= endOfDocumentTop) {
Logo.className = 'largeLogo';
size = 0;
}
}