justify-items

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CSS 的 justify-items 属性为所有盒中的项目定义了默认的 justify-self , 可以使这些项目以默认方式沿适当轴线对齐到每个盒子。

该属性的作用效果取决于我们使用的布局模式:

  • 在块级布局中,会将其包含的项目在其行内轴上对齐;
  • 绝对定位的元素中,会将其包含的项目在其行内轴上对齐,同时考虑 top、left、bottom、right 的值;
  • 表格单元中,该属性被忽略(块级元素、绝对定位元素和表格布局中对齐的更多信息);
  • 弹性盒子布局中,该属性被忽略(弹性盒子中对齐的更多信息);
  • 栅格布局中,会将其栅格区域内的项目在其行内轴上对齐(栅格布局中对齐的更多信息);

语法规则

/* Basic keywords */
justify-items: auto;
justify-items: normal;
justify-items: stretch;

/* Positional alignment */
justify-items: center;     /* Pack items around the center */
justify-items: start;      /* Pack items from the start */
justify-items: end;        /* Pack items from the end */
justify-items: flex-start; /* Pack flex items from the start */
justify-items: flex-end;   /* Pack flex items from the end */
justify-items: self-start;
justify-items: self-end;
justify-items: left;       /* Pack items from the left */
justify-items: right;      /* Pack items from the right */

/* Baseline alignment */
justify-items: baseline;
justify-items: first baseline;
justify-items: last baseline;

/* Overflow alignment (for positional alignment only) */
justify-items: safe center;
justify-items: unsafe center;

/* Legacy alignment */
justify-items: legacy right;
justify-items: legacy left;
justify-items: legacy center;

/* Global values */
justify-items: inherit;
justify-items: initial;
justify-items: unset;

This property can take one of four different forms:

  • Basic keywords: one of the keyword values normal, auto, or stretch.
  • Baseline alignment: the baseline keyword, plus optionally one of first or last.
  • Positional alignment: one of: center, start, end, flex-start, flex-end, self-start, self-end, left, or right. Plus optionally safe or unsafe.
  • Legacy alignment: the legacy keyword, followed by one of left or right.

auto
The value used is the value of the justify-items property of the parents box, unless the box has no parent, or is absolutely positioned, in these cases, auto represents normal.
normal
The effect of this keyword is dependent of the layout mode we are in:
  • In block-level layouts, the keyword is a synonym of start.
  • In absolutely-positioned layouts, the keyword behaved like start on replaced absolutely-positioned boxes, and as stretch on all other absolutely-positioned boxes.
  • In table cell layouts, this keyword has no meaning as this property is ignored.
  • In flexbox layouts, this keyword has no meaning as this property is ignored.
  • In grid layouts, this keyword leads to a behavior similar to the one of stretch, except for boxes with an aspect ratio or an intrinsic sizes where it behaves like start.
start
The item is packed flush to each other toward the start edge of the alignment container in the appropriate axis.
end
The item is packed flush to each other toward the end edge of the alignment container in the appropriate axis.
flex-start
For items that are not children of a flex container, this value is treated like start.
flex-end
For items that are not children of a flex container, this value is treated like end.
self-start
The item is packed flush to the edge of the alignment container of the start side of the item, in the appropriate axis.
self-end
The item is packed flush to the edge of the alignment container of the end side of the item, in the appropriate axis.
center
The items are packed flush to each other toward the center of the of the alignment container.
left
The items are packed flush to each other toward the left edge of the alignment container. If the property’s axis is not parallel with the inline axis, this value behaves like start.
right
The items are packed flush to each other toward the right edge of the alignment container in the appropriate axis. If the property’s axis is not parallel with the inline axis, this value behaves like start.
baseline
first baseline

last baseline
Specifies participation in first- or last-baseline alignment: aligns the alignment baseline of the box’s first or last baseline set with the corresponding baseline in the shared first or last baseline set of all the boxes in its baseline-sharing group.
The fallback alignment for first baseline is start, the one for last baseline is end.
stretch
If the combined size of the items is less than the size of the alignment container, any auto-sized items have their size increased equally (not proportionally), while still respecting the constraints imposed by max-height/max-width (or equivalent functionality), so that the combined size exactly fills the alignment container.
safe
If the size of the item overflows the alignment container, the item is instead aligned as if the alignment mode were start.
unsafe
Regardless of the relative sizes of the item and alignment container, the given alignment value is honored.
legacy
Makes the value inherited by the box descendants. Note that if a descendant has a justify-self: auto value, the legacy keyword is not considered by the descend, only the left, right, or center value associated to it.

Formal syntax

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

where
<baseline-position> = [ first | last ]? baseline
<overflow-position> = unsafe | safe
<self-position> = center | start | end | self-start | self-end | flex-start | flex-end

规范

Specification Status Comment
CSS Box Alignment Module Level 3
justify-items
Working Draft Initial definition
初始值legacy
适用元素all elements
是否是继承属性
适用媒体visual
计算值as specified
Animation typediscrete
正规顺序per grammar

浏览器兼容性

Support in Flex layout

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
Supported in Flex LayoutChrome Full support 52Edge Full support 12Firefox Full support 20IE Full support 11Opera Full support 12.1Safari Full support 9WebView Android Full support 52Chrome Android Full support 52Firefox Android Full support 20Opera Android Full support 12.1Safari iOS Full support 9Samsung Internet Android Full support 6.0

Legend

Full support  
Full support

Support in Grid layout

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
Supported in Grid LayoutChrome Full support 57Edge Full support 16Firefox Full support 45IE No support NoOpera Full support 44Safari Full support 10.1WebView Android Full support 57Chrome Android Full support 57Firefox Android Full support 45Opera Android Full support 43Safari iOS Full support 10.3Samsung Internet Android Full support 6.0

Legend

Full support  
Full support
No support  
No support

另见