前置知识:
CSS变量之var()函数的应用——动态修改样式 & root的使用
flex相关知识
场景: 动态设置给父元素内子元素设置每行排列几个
通过 document.body.style.setProperty('--itemNum', 5)
设置样式变量,然后通过给父元素设置display: flex;
,子元素设置flex: 0 0 calc(90% / var(--itemNum))
动态控制子元素的宽度
<!DOCTYPE html>
<html lang="en"><head><meta charset="UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=edge"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Document</title>
</head>
<style>.content {display: flex;flex-wrap: wrap;justify-content: flex-start;padding-bottom: 50px;padding-left: 40px;text-align: center;border:1px solid black;}.child {width: 100px;height: 100px;box-sizing: border-box;flex: 0 0 calc(90% / var(--itemNum));text-align: center;background-color: #d8ffff;border-radius: 47px;margin: 20px 0;margin-right:calc(10% / var(--itemNum));}
</style><body><div class="content"><div class="child"></div><div class="child"></div><div class="child"></div><div class="child"></div><div class="child"></div><div class="child"></div><div class="child"></div><div class="child"></div></div>
</body>
<script>document.body.style.setProperty('--itemNum', 5)</script>
</html>