place-items

CSS 的 **place-items** 简写属性允许您同时沿块方向和内联方向对齐项目（即在相关的布局系统（如网格或 Flexbox）中使用 align-items 和 justify-items 属性）。如果未设置第二个值，则第一个值也用于第二个值。

试一试

组成属性

此属性是以下 CSS 属性的简写形式

语法

css

/* Positional alignment */
place-items: center;
place-items: normal start;
place-items: center normal;
place-items: start legacy;
place-items: end normal;
place-items: self-start legacy;
place-items: self-end normal;
place-items: flex-start legacy;
place-items: flex-end normal;
place-items: anchor-center;

/* Baseline alignment */
place-items: baseline normal;
place-items: first baseline legacy;
place-items: last baseline normal;
place-items: stretch legacy;

/* Global values */
place-items: inherit;
place-items: initial;
place-items: revert;
place-items: revert-layer;
place-items: unset;

值

以下形式之一

单个 align-items 值，用于在块方向和内联方向上设置对齐方式。
一个 align-items 值，用于设置块方向上的对齐方式，后跟一个 justify-items 值，用于设置内联方向上的对齐方式。

正式定义

初始值	与简写形式的每个属性相同 `align-items`: `normal` `justify-items`: `legacy`
应用于	所有元素
继承	否
计算值	与简写形式的每个属性相同 `align-items`: 指定值 `justify-items`: 指定值
动画类型	离散

正式语法

place-items = 
  <'align-items'> <'justify-items'>?  

<align-items> = 
  normal                                    |
  stretch                                   |
  <baseline-position>                       |
  [ <overflow-position>? <self-position> ]  |
  anchor-center                             

<justify-items> = 
  normal                                              |
  stretch                                             |
  <baseline-position>                                 |
  <overflow-position>? [ <self-position> | left | right ]  |
  legacy                                              |
  legacy && [ left | right | center ]                 |
  anchor-center                                       

<baseline-position> = 
  [ first | last ]?  &&
  baseline           

<overflow-position> = 
  unsafe  |
  safe    

<self-position> = 
  center      |
  start       |
  end         |
  self-start  |
  self-end    |
  flex-start  |
  flex-end

示例

在弹性容器中放置项目

在 Flexbox 中，justify-self 或 justify-items 不适用，因为在主轴上，项目被视为一个组。因此，第二个值将被忽略。

div > div {
  box-sizing: border-box;
  border: 2px solid #8c8c8c;
  width: 50px;
  display: flex;
  align-items: center;
  justify-content: center;
}

#item1 {
  background-color: #8cffa0;
  min-height: 30px;
  font-size: 2em;
}

#item2 {
  background-color: #a0c8ff;
  min-height: 50px;
}

#item3 {
  background-color: #ffa08c;
  min-height: 40px;
}

#item4 {
  background-color: #ffff8c;
  min-height: 60px;
}

#item5 {
  background-color: #ff8cff;
  min-height: 70px;
}

#item6 {
  background-color: #8cffff;
  min-height: 50px;
}

select {
  font-size: 16px;
}

.row {
  margin-top: 10px;
}

<div id="container">
  <div id="item1">1</div>
  <div id="item2">2</div>
  <div id="item3">3</div>
</div>

<div class="row">
  <label for="values">place-items: </label>
  <select id="values">
    <option value="stretch">stretch</option>
    <option value="start">start</option>
    <option value="center">center</option>
    <option value="end">end</option>
    <option value="left">left</option>
    <option value="right">right</option>
    <option value="auto center">auto center</option>
    <option value="normal start">normal start</option>
    <option value="center normal">center normal</option>
    <option value="start auto">start auto</option>
    <option value="end normal">end normal</option>
    <option value="self-start auto">self-start auto</option>
    <option value="self-end normal">self-end normal</option>
    <option value="flex-start auto">flex-start auto</option>
    <option value="flex-end normal">flex-end normal</option>
    <option value="left auto">left auto</option>
    <option value="right normal">right normal</option>
    <option value="baseline normal">baseline normal</option>
    <option value="first baseline auto">first baseline auto</option>
    <option value="last baseline normal">last baseline normal</option>
    <option value="stretch auto">stretch auto</option>
  </select>
</div>

const values = document.getElementById("values");
const container = document.getElementById("container");

values.addEventListener("change", (evt) => {
  container.style.placeItems = evt.target.value;
});

CSS

css

#container {
  height: 200px;
  width: 240px;
  place-items: stretch; /* You can change this value by selecting another option in the list */
  background-color: #8c8c8c;
  display: flex;
}

结果

在网格容器中放置项目

以下网格容器包含的项目小于其放置的网格区域，因此 place-items 将在块方向和内联方向上移动它们。

div > div {
  box-sizing: border-box;
  border: 2px solid #8c8c8c;
}

#item1 {
  background-color: #8cffa0;
  min-height: 30px;
  font-size: 2em;
}

#item2 {
  background-color: #a0c8ff;
  min-height: 50px;
}

#item3 {
  background-color: #ffa08c;
  min-height: 40px;
}

#item4 {
  background-color: #ffff8c;
  min-height: 60px;
}

#item5 {
  background-color: #ff8cff;
  min-height: 70px;
}

#item6 {
  background-color: #8cffff;
  min-height: 50px;
}

select {
  font-size: 16px;
}

.row {
  margin-top: 10px;
}

<div id="gridcontainer">
  <div id="item1">1</div>
  <div id="item2">2</div>
  <div id="item3">3</div>
  <div id="item4">4</div>
  <div id="item5">5</div>
</div>

<div class="row">
  <label for="gridvalues">place-items: </label>
  <select id="gridvalues">
    <option value="stretch">stretch</option>
    <option value="start">start</option>
    <option value="center">center</option>
    <option value="end">end</option>
    <option value="left">left</option>
    <option value="right">right</option>
    <option value="auto center">auto center</option>
    <option value="normal start">normal start</option>
    <option value="center normal">center normal</option>
    <option value="start auto">start auto</option>
    <option value="end normal">end normal</option>
    <option value="self-start auto">self-start auto</option>
    <option value="self-end normal">self-end normal</option>
    <option value="flex-start auto">flex-start auto</option>
    <option value="flex-end normal">flex-end normal</option>
    <option value="left auto">left auto</option>
    <option value="right normal">right normal</option>
    <option value="baseline normal">baseline normal</option>
    <option value="first baseline auto">first baseline auto</option>
    <option value="last baseline normal">last baseline normal</option>
    <option value="stretch auto">stretch auto</option>
  </select>
</div>

const values = document.getElementById("gridvalues");
const container = document.getElementById("gridcontainer");

values.addEventListener("change", (evt) => {
  container.style.placeItems = evt.target.value;
});

CSS

css

#gridcontainer {
  height: 200px;
  width: 240px;
  place-items: stretch; /* You can change this value by selecting another option in the list */
  background-color: #8c8c8c;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
}

#gridcontainer > div {
  width: 50px;
}

结果

规范

规范
CSS 盒子对齐模块级别 3 # place-items 属性

浏览器兼容性

BCD 表格仅在启用 JavaScript 的浏览器中加载。