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• 句法
• 描述
• 形式定义
• 形式句法
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

mask-border-slice CSS property divides the image set by mask-border-source into regions. These regions are used to form the components of an element's mask border .

句法

/* All sides */
mask-border-slice: 30%;
/* vertical | horizontal */
mask-border-slice: 10% 30%;
/* top | horizontal | bottom */
mask-border-slice: 30 30% 45;
/* top | right | bottom | left */
mask-border-slice: 7 12 14 5;
/* Using the `fill` keyword */
mask-border-slice: 10% fill 7 12;
/* Global values */
mask-border-slice: inherit;
mask-border-slice: initial;
mask-border-slice: unset;
					

mask-border-slice property may be specified using one to four <number-percentage> values to represent the position of each image slice. Negative values are invalid; values greater than their corresponding dimension are clamped to 100% .

• When one position is specified, it creates all four slices at the same distance from their respective sides.
• When two positions are specified, the first value creates slices measured from the top and bottom , the second creates slices measured from the left and right .
• When three positions are specified, the first value creates a slice measured from the top , the second creates slices measured from the left and right , the third creates a slice measured from the bottom .
• When four positions are specified, they create slices measured from the top , right , bottom ，和 left in that order (clockwise).

可选 fill value, if used, can be placed anywhere in the declaration.

值

<number>

Represents an edge offset in pixels for raster images and coordinates for vector images. For vector images, the number is relative to the element's size, not the size of the source image, so percentages are generally preferable in these cases.

<percentage>

Represents an edge offset as a percentage of the source image's size: the width of the image for horizontal offsets, the height for vertical offsets.

fill

Preserves the middle image region. Its width and height are sized to match the top and left image regions, respectively.

描述

The slicing process creates nine regions in total: four corners, four edges, and a middle region. Four slice lines, set a given distance from their respective sides, control the size of the regions.

The above diagram illustrates the location of each region.

• Zones 1-4 are corner regions . Each one is used a single time to form the corners of the final border image.
• Zones 5-8 are edge regions . These are repeated, scaled, or otherwise modified in the final border image to match the dimensions of the element.
• Zone 9 is the middle region . It is discarded by default, but is used like a background image if the keyword fill 有设置。

mask-border-repeat , mask-border-width ，和 mask-border-outset properties determine how these regions are used to form the final mask border.

形式定义

初始值	0
适用于	all elements; In SVG, it applies to container elements excluding the defs element and all graphics elements
继承	no
百分比	refer to size of the mask border image
计算值	如指定
动画类型	discrete

形式句法

<number-percentage>{1,4} fill?
where 
<number-percentage> = <number> | <percentage>
					

范例

基本用法

This property doesn't appear to be supported anywhere yet. When it eventually starts to be supported, it will serve to define the size of the slices taken from the source image, and used to create the border mask.

mask-border-slice: 30 fill;
					

Chromium-based browsers support an outdated version of this property — mask-box-image-slice — with a prefix:

-webkit-mask-box-image-slice: 30 fill;
					

注意 : The mask-border page features a working example (using the out-of-date prefixed border mask properties supported in Chromium), so you can get an idea of the effect.

注意 : The fill keyword needs to be included if you want the element's content to be visible.

规范

规范	状态	注释
CSS Masking Module Level 1 The definition of 'mask-border-slice' in that specification.	候选推荐	Initial defintion

浏览器兼容性

TBD

另请参阅

• Illustrated description of the 1-to-4-value syntax

元数据

• 最后修改： Aug 5, 2020

相关话题

1. CSS
2. CSS 参考
3. CSS Masking
4. 特性

   1. clip
   2. clip-path
   3. mask
   4. mask-border
   5. mask-border-mode
   6. mask-border-outset
   7. mask-border-repeat
   8. mask-border-slice
   9. mask-border-source
   10. mask-border-width
   11. mask-clip
   12. mask-composite
   13. mask-image
   14. mask-mode
   15. mask-origin
   16. mask-position
   17. mask-repeat
   18. mask-size
   19. mask-type