Question

我正在尝试使用导航栏，当用户向上滚动时，导航项会被拉起并且徽标会随着用户向下滚动而缩小。

但是目前导航项目在上升之前会下降...当它恢复时它会在不同的位置结束......

HTML：

<nav class="navbar">
 <a href="#">James Jones</a>
  <ul class="nav-items">
   <li><a href="#about">About</a></li>
   <li><a href="#">Work</a></li>
   <li><a href="#">Photography</a></li>
   <li><a href="#">Videos</a></li>
   <li><a href="#">Contact</a></li>
  </ul>
</nav>

CSS：

.navbar {
  background: #fff;
  font-family: ShorelinesScriptBold;
  font-size: 2em;
  font-weight: 900;
  height: 150px;
  line-height: 100px;
  position: fixed;
  text-align: center;
  -webkit-transition: all 1.0s ease;
  transition: all 1.0s ease;
  width: 100%;
  z-index: 10000;
}

.navbar a {
  color: #343434;
  display: block;
  /*margin: 0 0 -24px 0;*/
  margin: 0 0 -55px 0;
  text-decoration: none;
}

.navbar a:hover {
  color: #343434;
  text-decoration: none;
}

.shrink {
  font-family: 'Radley', serif;
  font-size: 1em;
  font-weight: 500;
  height: 50px;
  letter-spacing: 1px;
  line-height: 50px;
  position: fixed;
  top: -5px;
  text-transform: uppercase;
}

.nav-items {
  background: #fff;
  -webkit-transition: all 1.0s ease;
  transition: all 1.0s ease;
}

.nav-items li {
  display: inline-block;
  font-family: Helvetica;
  font-size: 12px;
  letter-spacing: 0;
  text-transform: uppercase;
}

.nav-items a {
  color: gray;
  font-weight: 300;
  margin: 0 15px;
  text-decoration: none;
}

.nav-items a:hover {
  color: #FFAED8;
}

.margin {
  margin: 30px 0 0 0;
}

使用Javascript：

$(window).scroll(function() {
   if ($(document).scrollTop() > 150) {
     $('.navbar').addClass('shrink');
     $('.nav-items').addClass('margin');
   } else {
     $('.navbar').removeClass('shrink');
     $('.nav-items').addClass('margin');
   }
});

JS FIDDLE：

https://jsfiddle.net/gkrtk8s3/4/

Answer 1

您在菜单栏上遇到冒泡运动的原因是因为您有

.nav-items {
  background: #fff;
  -webkit-transition: all 1.0s ease;/* Duplicate Transition. you already have a transition on your nav tag
  transition: all 1.0s ease; /* Duplicate Transition. you already have a transition on your nav tag
}

从上方取出两行-webkit-transition: all 1.0s ease和transition: all 1.0s ease;

注意：在Chrome版本46.0.2490.71

中测试

CSS动画在重新开始之前就会掉落

1 个答案: