break-after - CSS（层叠样式表） 编辑

break-after CSS 属性描述在生成的盒子之后的页面，列或区域中断行为（换句话说，如何以及是否中断）。如果没有生成的盒子，则该属性将被忽略。

/* Generic break values */
break-after: auto;
break-after: avoid;
break-after: always;
break-after: all;

/* Page break values */
break-after: avoid-page;
break-after: page;
break-after: left;
break-after: right;
break-after: recto;
break-after: verso;

/* Column break values */
break-after: avoid-column;
break-after: column;

/* Region break values */
break-after: avoid-region;
break-after: region;

/* Global values */
break-after: inherit;
break-after: initial;
break-after: unset;

每个潜在的断点（亦即每个元素的边界）都受到三个属性的影响：上一个元素的 break-after 值、下一个元素的 break-before 值以及当前元素自身的 break-inside 值。

以下规则被用于判断中断是否必要：

1. 如果上述三个属性中，如果任何一个的值属于“强制中断”值，那么这个属性将被优先应用，此处所称“强制中断”的值为： always、 left、 right、 page、 column 和 region。If several of the concerned values is such a break, the one of the element that appears the latest in the flow is taken (that is the break-before value has precedence over the break-after value, which itself has precedence over the break-inside value).
2. If any of the three concerned values is an avoid break value, that is avoid, avoid-page, avoid-region, avoid-column, no such break will be applied at that point.

Once forced breaks have been applied, soft breaks may be added if needed, but not on element boundaries that resolve in a corresponding avoid value.

初始值	auto
适用元素	block-level elements
是否是继承属性	否
计算值	as specified
Animation type	discrete

语法

The break-after property is specified as one of the keyword values from the list below.

属性值

Generic break values

auto

Allows, but does not force, any break (page, column, or region) to be inserted right after the principal box.

avoid

Avoids any break (page, column, or region) from being inserted right after the principal box.

always

Forces a page break right after the principal box. The type of this break is that of the immediately-containing fragmentation context. If we are inside a multicol container then it would force a column break, inside paged media (but not inside a multicol container) a page break.

all

Forces a page break right after the principal box. Breaking through all possible fragmentation contexts. So a break inside a multicol container, which was inside a page container would force a column and page break.

Page break values

avoid-page

Avoids any page break right after the principal box.

page

Forces a page break right after the principal box.

left

Forces one or two page breaks right after the principal box, whichever will make the next page into a left page.

right

Forces one or two page breaks right after the principal box, whichever will make the next page into a right page.

recto

Forces one or two page breaks right after the principal box, whichever will make the next page into a recto page. (A recto page is a right page in a left-to-right spread or a left page in a right-to-left spread.)

verso

Forces one or two page breaks right after the principal box, whichever will make the next page into a verso page. (A verso page is a left page in a left-to-right spread or a left right in a right-to-left spread.)

Column break values

avoid-column

Avoids any column break right after the principal box.

column

Forces a column break right after the principal box.

Region break values

avoid-region

Avoids any region break right after the principal box.

region

Forces a region break right after the principal box.

形式化语法

auto | avoid | always | all | avoid-page | page | left | right | recto | verso | avoid-column | column | avoid-region | region

Page break aliases

For compatibility reasons, the legacy page-break-after property should be treated by browsers as an alias of break-after. This ensures that sites using page-break-after continue to work as designed. A subset of values should be aliased as follows:

page-break-after	break-after
auto	auto
left	left
right	right
avoid	avoid
always	page

The always value of page-break-* was implemented by browsers as a page break, and not as a column break. Therefore the aliasing is to page, rather than the always value in the Level 4 spec.

规范

规范	状态	备注
CSS Fragmentation Module Level 3 break-after	Candidate Recommendation	Adds the recto and verso keywords. Changes the media type of this property from paged to visual. Defines the breaking algorithm with different kinds of breaks.
CSS Regions Module Level 1 break-after	Working Draft	Extends the property to handle region breaks. Adds the avoid-region and region keywords.
CSS Multi-column Layout Module break-after	Working Draft	Initial definition. Extends the CSS 2.1 page-break-after property to handle both page and column breaks.

浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

Support in multi-column layout

BCD tables only load in the browser

Support in paged media

BCD tables only load in the browser