演示地址
Progress Steps (50projects50days.com)
实现思路
结构样式方面主要是flex弹性布局，绝对定位，并且添加过渡效果。
利用currentActive来存储当前状态，监听prev、next点击事件来改变进度状态
代码
html结构
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>进度步骤条</title>
<link rel="stylesheet" href="style.css">
</head>
<body>
<div class="container">
<div class="progress-container">
<div class="progress" id="progress"></div>
<div class="circle active">1</div>
<div class="circle">2</div>
<div class="circle">3</div>
<div class="circle">4</div>
</div>
<button class="btn" id="prev" disabled>Prev</button>
<button class="btn" id="next">Next</button>
</div>
<script src="./script.js"></script>
</body>
</html>
css样式
* {
box-sizing: border-box;
}
:root {
--line-border-fill: #3498db;
--line-border-empty: #e0e0e0;
}
body {
/* 弹性布局，垂直居中 */
display: flex;
justify-content: center;
align-items: center;
height: 100vh;
background: #f6f7fb;
}
.container {
/* 文本水平居中，这里目的是让按钮居中 */
text-align: center;
}
.progress-container {
/* 子元素绝对定位，父元素相对定位 */
position: relative;
/* 弹性布局，水平方向分散，垂直方向居中 */
display: flex;
justify-content: space-between;
align-items: center;
margin-bottom: 30px;
width: 320px;
}
.progress-container::before {
content: "";
position: absolute;
top: 50%;
left: 0;
z-index: -1;
/* Y轴负方向变换自身高度的一半，目的是与圆圈居中对齐 */
transform: translateY(-50%);
width: 100%;
height: 4px;
background-color: var(--line-border-empty);
transition: all 0.4s ease;
}
.progress {
position: absolute;
top: 50%;
left: 0;
z-index: -1;
transform: translateY(-50%);
width: 0%;
height: 4px;
background-color: var(--line-border-fill);
transition: all 0.4s ease;
}
.circle {
display: flex;
justify-content: center;
align-items: center;
width: 30px;
height: 30px;
color: #999;
background: #fff;
border-radius: 50%;
border: 3px solid var(--line-border-empty);
transition: border 0.4s ease;
}
.circle.active {
/* 激活时改变边框颜色 */
border: 3px solid var(--line-border-fill);
}
.btn {
padding: 10px 30px;
margin: 5px;
background-color: var(--line-border-fill);
border: 0;
border-radius: 6px;
color: #fff;
font-size: 14px;
}
.btn:active {
/* 点击按钮时缩放大小，产生回弹的视觉 */
transform: scale(0.98);
}
/* 按钮不可用时样式 */
.btn:disabled {
background-color: var(--line-border-empty);
cursor: not-allowed;
}
js行为
// 定义需要用到的dom对象
const progress = document.getElementById('progress')
const prev = document.getElementById('prev');
const next = document.getElementById('next');
const circles = document.querySelectorAll('.circle')
// 保存当前进度步骤数
let currentActive = 1;
prev.addEventListener('click', () => {
//当currentActive大于1时，可以回退到前一步
if (currentActive > 1) {
currentActive--;
update();
}
})
next.addEventListener('click', () => {
// 当currentActive小于步骤数量时可以前进一步
if (currentActive < circles.length) {
currentActive++;
update();
}
})
function update() {
// 更新步骤数
circles.forEach((circle, index) => {
if (index < currentActive) {
circle.classList.add('active')
} else {
circle.classList.remove('active')
}
})
// 更新进度百分比，circles.length - 1是因为分段数总是比步骤数少一
progress.style.width = (currentActive - 1) / (circles.length - 1) * 100 + '%';
// 更新按钮状态，步骤时prev按钮不可用，当前进度最终步骤时next按钮不可用
if (currentActive === 1) {
prev.disabled = true
} else if (currentActive === circles.length) {
next.disabled = true
} else {
prev.disabled = false
next.disabled = false
}
}
参考资料：50 Projects 50 Days | Traversy Media
50 unique mini-projects to sharpen your HTML, CSS & JavaScript skills
