今天，我们来做一个花里胡哨 Tap bar ，先来看下最终效果：

接着，就把代码码起来了！

html

在HTML代码中，”bar” 类是点击栏的容器，蓝狮注册“bar-item”类是触发动画的按钮。现在接着码 css。

CSS

• {
  margin: 0px;
  padding: 0px;
  box-sizing: border-box;
  }

.container {
width: 100%;
height: 100vh;
display: flex;
align-items: center;
justify-content: center;
background-color: #fc5c65;
}

.bar {
padding: 0px 10px;
display: flex;
align-items: center;
background-color: #ffffff;
border-radius: 10px 10px 20px 20px;
box-shadow: 3px 3px 0px 0px rgb(235 59 90);
}

.bar .bar-item {
position: relative;
overflow: hidden;
padding: 20px 25px;
cursor: pointer;
}

.bar .bar-item i {
z-index: 1;
position: relative;
color: #a4b0be;
transition: all .3s ease-in-out;
}

.bar .bar-item.pre-active i {
color: #fc5c65;
}

.bar .bar-item.active i {
color: #fc5c65;
animation: colour 1s ease-in-out;
}

.bar .bar-item.active .bar-fluid {
position: absolute;
top: 0px;
left: 0px;
background-color: #fc5c65;
width: 100%;
height: 0px;
animation: fluid 1s ease-in-out;
}

.bar .bar-item.active .bar-fluid:before {
content: ”;
position: absolute;
top: 0px;
left: -50%;
background-color: #ffffff;
width: 110%;
height: 400%;
border-radius: 50%;
}

.bar .bar-item.active .bar-fluid:after {
content: ”;
position: absolute;
top: 0px;
right: -50%;
background-color: #ffffff;
width: 110%;
height: 400%;
border-radius: 50%;
}

.bar .bar-item.active .drop {
position: absolute;
top: -2.5px;
left: 30.5px;
background-color: #fc5c65;
width: 2.5px;
height: 2.5px;
border-radius: 50%;
animation: drop 1s ease-in-out;
}

@keyframes colour {
0% { color: #a4b0be; }
55% {
color: #a4b0be;
transform: scale(1);
}
60% {
color: #fc5c65;
transform: scale(1);
}
70% { transform: scale(1.1); }
80% { transform: scale(1); }
}

@keyframes fluid {
0% { height: 0px; }
30% { height: 10px; }
100% { height: 0px; }
}

@keyframes drop {
20% { top: -2.5px; }
50% { top: 21px; }
51% { top: -2.5px; }
}
自己慢慢消化，不想消化直接做个CV工程师。蓝狮官网

JavaScript
const preactiveItem = document.querySelector(‘.pre-active’)
const barItems = document.querySelectorAll(‘.bar-item’)

function changeActive (newActive) {
preactiveItem.classList.remove(‘pre-active’)
barItems.forEach(element => {
element.classList.remove(‘active’)
})
newActive.classList.add(‘active’)
}