mask-image - CSS（层叠样式表） 编辑

这是一个实验中的功能
此功能某些浏览器尚在开发中，请参考浏览器兼容性表格以得到在不同浏览器中适合使用的前缀。由于该功能对应的标准文档可能被重新修订，所以在未来版本的浏览器中该功能的语法和行为可能随之改变。

概要

mask-image CSS属性用于设置元素上遮罩层的图像。

初始值	none
适用元素	all elements; In SVG, it applies to container elements excluding the defs element and all graphics elements
是否是继承属性	否
计算值	as specified, but with url values made absolute
Animation type	discrete

语法

/* Keyword value */
mask-image: none;

/* <mask-source> value */
mask-image: url(masks.svg#mask1);

/* <image< values */
mask-image: linear-gradient(rgba(0, 0, 0, 1.0), transparent);
mask-image: image(url(mask.png), skyblue);

/* Multiple values */
mask-image: image(url(mask.png), skyblue), linear-gradient(rgba(0, 0, 0, 1.0), transparent);

/* Global values */
mask-image: inherit;
mask-image: initial;
mask-image: unset;

Values

none

默认值，透明的黑色图像层，也就是没有遮罩层。

<mask-source>

<mask>或CSS图像的url

<image>

图片作为遮罩层

Formal syntax

<mask-reference>#
where 
<mask-reference> = none | <image> | <mask-source>
where 
<image> = <url> | <image()> | <image-set()> | <element()> | <paint()> | <cross-fade()> | <gradient>
<mask-source> = <url>
where 
<image()> = image( <image-tags>? [ <image-src>? , <color>? ]! )
<image-set()> = image-set( <image-set-option># )
<element()> = element( <id-selector> )
<paint()> = paint( <ident>, <declaration-value>? )
<cross-fade()> = cross-fade( <cf-mixing-image> , <cf-final-image>? )
<gradient> = <linear-gradient()> | <repeating-linear-gradient()> | <radial-gradient()> | <repeating-radial-gradient()> | <conic-gradient()>
where 
<image-tags> = ltr | rtl
<image-src> = <url> | <string>
<color> = <rgb()> | <rgba()> | <hsl()> | <hsla()> | <hex-color> | <named-color> | currentcolor | <deprecated-system-color>
<image-set-option> = [ <image> | <string> ] <resolution>
<id-selector> = <hash-token>
<cf-mixing-image> = <percentage>? && <image>
<cf-final-image> = <image> | <color>
<linear-gradient()> = linear-gradient( [ <angle> | to <side-or-corner> ]? , <color-stop-list> )
<repeating-linear-gradient()> = repeating-linear-gradient( [ <angle> | to <side-or-corner> ]? , <color-stop-list> )
<radial-gradient()> = radial-gradient( [ <ending-shape> || <size> ]? [ at <position> ]? , <color-stop-list> )
<repeating-radial-gradient()> = repeating-radial-gradient( [ <ending-shape> || <size> ]? [ at <position> ]? , <color-stop-list> )
<conic-gradient()> = conic-gradient( [ from <angle> ]? [ at <position> ]?, <angular-color-stop-list> )
where 
<rgb()> = rgb( <percentage>{3} [ / <alpha-value> ]? ) | rgb( <number>{3} [ / <alpha-value> ]? ) | rgb( <percentage>#{3} , <alpha-value>? ) | rgb( <number>#{3} , <alpha-value>? )
<rgba()> = rgba( <percentage>{3} [ / <alpha-value> ]? ) | rgba( <number>{3} [ / <alpha-value> ]? ) | rgba( <percentage>#{3} , <alpha-value>? ) | rgba( <number>#{3} , <alpha-value>? )
<hsl()> = hsl( <hue> <percentage> <percentage> [ / <alpha-value> ]? ) | hsl( <hue>, <percentage>, <percentage>, <alpha-value>? )
<hsla()> = hsla( <hue> <percentage> <percentage> [ / <alpha-value> ]? ) | hsla( <hue>, <percentage>, <percentage>, <alpha-value>? )
<side-or-corner> = [ left | right ] || [ top | bottom ]
<color-stop-list> = [ <linear-color-stop> [, <linear-color-hint>]? ]# , <linear-color-stop>
<ending-shape> = circle | ellipse
<size> = closest-side | farthest-side | closest-corner | farthest-corner | <length> | <length-percentage>{2}
<position> = [ [ left | center | right ] || [ top | center | bottom ] | [ left | center | right | <length-percentage> ] [ top | center | bottom | <length-percentage> ]? | [ [ left | right ] <length-percentage> ] && [ [ top | bottom ] <length-percentage> ] ]
<angular-color-stop-list> = [ <angular-color-stop> [, <angular-color-hint>]? ]# , <angular-color-stop>
where 
<alpha-value> = <number> | <percentage>
<hue> = <number> | <angle>
<linear-color-stop> = <color> <color-stop-length>?
<linear-color-hint> = <length-percentage>
<length-percentage> = <length> | <percentage>
<angular-color-stop> = <color> && <color-stop-angle>?
<angular-color-hint> = <angle-percentage>
where 
<color-stop-length> = <length-percentage>{1,2}
<color-stop-angle> = <angle-percentage>{1,2}
<angle-percentage> = <angle> | <percentage>

例子

CSS

#masked {
  width: 100px;
  height: 100px;
  background-color: #8cffa0;
  mask-image: url(https://mdn.mozillademos.org/files/12676/star.svg);
  -webkit-mask-image: url(https://mdn.mozillademos.org/files/12676/star.svg);
}

HTML

<div id="masked"></div>

Specifications

Specification	Status	Comment
CSS Masking Module Level 1 mask-image	Candidate Recommendation	Initial definition

浏览器兼容性

We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains. Find out how you can help!

• Desktop
• Mobile

Feature	Chrome	Firefox (Gecko)	Internet Explorer	Edge	Opera	Safari (WebKit)
Basic support	1.0-webkit[1]	未实现[2]	未实现	?	(Yes)-webkit	4.0-webkit[3]
Multiple mask images	1.0-webkit	未实现[2]	未实现	?	(Yes)-webkit	4.0-webkit
SVG masks	8.0	未实现[2]	未实现	?	(Yes)-webkit	4.0-webkit

Feature	Android	Firefox Mobile (Gecko)	IE Phone	Opera Mobile	Safari Mobile
Basic support	2.1-webkit[4]	未实现[2]	?	未实现	3.2-webkit[5]
Multiple mask images	(Yes)-webkit	未实现[2]	?	未实现	(Yes)-webkit
SVG masks	(Yes)-webkit	未实现[2]	?	未实现	(Yes)-webkit

[1] Implemented in version 8.0, Chrome initially only supported the -webkit prefixed versions of gradients as values. Later, support for the unprefixed versions was added.

[2] This feature is not implemented yet. It is only available in Nightly and Dev Edition. See bug 1251161.

[3] Implemented in version 4.0, Safari initially only supported the -webkit prefixed versions of gradients as values.

[4] Android initially only supported the -webkit prefixed versions of gradients as values.

[5] iOS Safari initially only supported the -webkit prefixed versions of gradients as values.