七种居中布局技巧-优快云博客

本文链接：https://blog.youkuaiyun.com/rainylululululu/article/details/105940436

共7种方法

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    *{
      margin: 0;
      padding: 0;
    }

    /* 法1：父设置宽高，并且text-align:center;line-height:父高度;
            子设置宽高，并且vertical-align:middle;display:inline-block
     */
    /* .outer{
      width: 100vw;
      height: 100vh;
      background-color: green;
      text-align: center;
      line-height: 100vh;
    }
    .inner{
      width: 100px;
      height: 100px;
      background-color: red;
      display: inline-block;
      vertical-align: middle;
    } */

/* 法2：父设置宽高，并且display:table-cell;text-align:center;vertical-align:middle
        子设置宽高，并且display:inline-block;
 */
    /* .outer{
      width: 100vw;
      height: 100vh;
      background-color: green;
      display: table-cell;
      text-align: center;
      vertical-align: middle;
    }
    .inner{
      width: 100px;
      height: 100px;
      background-color: red;
      display: inline-block;
    } */

/* 法3：父设置宽高，并且position:relative
        子设置宽高，并且position:absolute;top:50%;left:50%;transform: translate(-50%,-50%);
 */
 /* .outer{
      width: 100vw;
      height: 100vh;
      background-color: green;
      position: relative;
    }
    .inner{
      width: 100px;
      height: 100px;
      background-color: red;
      position: absolute;
      top: 50%;
      left: 50%;
      transform: translate(-50%,-50%);
    } */

  /* 法4：父设置宽高，并且display:flex;justify-content:center;align-items:center */
  /* .outer{
      width: 100vw;
      height: 100vh;
      background-color: green;
      display: flex;
      justify-content: center;
      align-items: center;
    }
    .inner{
      width: 100px;
      height: 100px;
      background-color: red;
    } */

  /* 法5：使用calc基于当前页面布局进行设计 */
  /* .outer{
      width: 100vw;
      height: 100vh;
      background-color: green;
      position: relative;
    }
    .inner{
      width: 100px;
      height: 100px;
      position: absolute;
      background-color: red;
      left: calc(50% - 50px);
      top: calc(50% - 50px);
    } */

  /* 法6：父设置宽高，relative 
          子设置宽高，absolute,top,left,复margin
  */
    /* .outer{
      width: 100vw;
      height: 100vh;
      background-color: green;
      position: relative;
    }
    .inner{
      width: 100px;
      height: 100px;
      position: absolute;
      background-color: red;
      left: 50%;
      top: 50%;
      margin-top: -50px;
      margin-left: -50px;
    }  */

    /* 法7：父设置：position:relative
            子设置top,right,bottom,left都是0，margin:auto */
    .outer{
      width: 100vw;
      height: 100vh;
      background-color: green;
      position: relative;
    }
    .inner{
      width: 100px;
      height: 100px;
      position: absolute;
      background-color: red;
      top: 0;
      right: 0;
      bottom: 0;
      left: 0;
      margin: auto;
    }

  </style>
</head>
<body>
  <div class="outer">
    <div class="inner">
    </div>
  </div>
</body>
</html>