关于不定宽高元素的居中_flutter inline-block-优快云博客

本文链接：https://blog.youkuaiyun.com/qq_41960337/article/details/88668753

水平居中

（1）inline-block + text-align

<!doctype html>
<html lang="en">
<head>
  <title>Document</title>
  <style>
    .parent{
      width: 400px;
      height: 100px;
      background: #bbb;
      text-align: center;
    }
    .child{
      display: inline-block;
      width: 100px;
      height: 100px;
      background: #333;
    }
  </style>
</head>
<body>
  <div class="parent">
    <div class="child"></div>
  </div>
</body>
</html>

(2) table + margin

<!doctype html>
<html lang="en">
<head>
  <title>Document</title>
  <style>
    .parent{
      width: 400px;
      height: 100px;
      background: #bbb;
    }
    .child{
      display: table;
      margin: 0 auto;
      width: 100px;
      height: 100px;
      background: #333;
    }
  </style>
</head>
<body>
  <div class="parent">
    <div class="child"></div>
  </div>
</body>
</html>

(3) absolute + transform

<!doctype html>
<html lang="en">
<head>
  <title>Document</title>
  <style>
    .parent{
      position: relative;
      width: 400px;
      height: 100px;
      background: #bbb;
    }
    .child{
      position: absolute;
      left: 50%;
      transform: translateX(-50%);
      width: 100px;
      height: 100px;
      background: #333;
    }
  </style>
</head>
<body>
  <div class="parent">
    <div class="child"></div>
  </div>
</body>
</html>

(4) flex + justify-content

<!doctype html>
<html lang="en">
<head>
  <title>Document</title>
  <style>
    .parent{
      display: flex;
      justify-content: center;
      width: 400px;
      height: 100px;
      background: #bbb;
    }
    .child{
      width: 100px;
      height: 100px;
      background: #333;
    }
  </style>
</head>
<body>
  <div class="parent">
    <div class="child"></div>
  </div>
</body>
</html>

2. 垂直居中

（1） table-cell + vertical-align

<!doctype html>
<html lang="en">
<head>
  <title>Document</title>
  <style>
    .parent{
      display: table-cell;
      vertical-align: middle;
      width: 100px;
      height: 400px;
      background: #bbb;
    }
    .child{
      width: 100px;
      height: 100px;
      background: #333;
    }
  </style>
</head>
<body>
  <div class="parent">
    <div class="child"></div>
  </div>
</body>
</html>

(2) absolute + transform

<!doctype html>
<html lang="en">
<head>
  <title>Document</title>
  <style>
    .parent{
      position: relative;
      width: 100px;
      height: 400px;
      background: #bbb;
    }
    .child{
      position: absolute;
      top: 50%;
      transform: translateY(-50%);
      width: 100px;
      height: 100px;
      background: #333;
    }
  </style>
</head>
<body>
  <div class="parent">
    <div class="child"></div>
  </div>
</body>
</html>

(4) flex + align-items

<!doctype html>
<html lang="en">
<head>
  <title>Document</title>
  <style>
    .parent{
      display: flex;
      align-items: center;
      width: 100px;
      height: 400px;
      background: #bbb;
    }
    .child{
      width: 100px;
      height: 100px;
      background: #333;
    }
  </style>
</head>
<body>
  <div class="parent">
    <div class="child"></div>
  </div>
</body>
</html>

3. 水平垂直居中

（1）inline-block + text-align + table-cell + vertical-algin

<!doctype html>
<html lang="en">
<head>
  <title>Document</title>
  <style>
    .parent{
      display: table-cell;
      vertical-align: middle;
      text-align: center;
      width: 400px;
      height: 400px;
      background: #bbb;
    }
    .child{
      display: inline-block;
      width: 100px;
      height: 100px;
      background: #333;
    }
  </style>
</head>
<body>
  <div class="parent">
    <div class="child"></div>
  </div>
</body>
</html>

(2) absolute + transform

<!doctype html>
<html lang="en">
<head>
  <title>Document</title>
  <style>
    .parent{
      position: relative;
      width: 400px;
      height: 400px;
      background: #bbb;
    }
    .child{
      position: absolute;
      left: 50%;
      top: 50%;
      transform: translate3d(-50%, -50%, 0);
      width: 100px;
      height: 100px;
      background: #333;
    }
  </style>
</head>
<body>
  <div class="parent">
    <div class="child"></div>
  </div>
</body>
</html>

(3) flex + justify-content + align-items

<!doctype html>
<html lang="en">
<head>
  <title>Document</title>
  <style>
    .parent{
      display: flex;
      justify-content: center;
      align-items: center;
      width: 400px;
      height: 400px;
      background: #bbb;
    }
    .child{

      width: 100px;
      height: 100px;
      background: #333;
    }
  </style>
</head>
<body>
  <div class="parent">
    <div class="child"></div>
  </div>
</body>
</html>