CSSRule
Baseline
Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since 2015年7月.
CSSRule 接口表示一条 CSS 规则。有几种不同的规则类型,在下面的类型常量部分中有悉数列出。
CSSRule 接口指定了所有类型的规则的公共属性,而特定类型的规则的专有属性则在这些规则各自类型的、更专用的接口中被指定。
可以通过 CSSStyleSheet 的 cssRules 列表了解更多关于 CSSRule 的介绍。
所有 CSSRule 实例共有的属性
CSSRule.cssText-
返回规则的文本表示。例如
"h1,h2 { font-size: 16pt }" CSSRule.parentRule只读-
返回包含规则,否则返回
null。例如:如果此规则是@media块中的样式规则,则其父规则将是该CSSMediaRule。 CSSRule.parentStyleSheet只读-
返回包含此规则的样式表的
CSSStyleSheet对象。 CSSRule.type只读-
规则类型,表示 CSS 规则类型 类型常量 中的一种类型。
常量
>类型常量
CSSRule 接口通过一系列整型常量来约束 CSSRule 的 type 取值范围,同时这些常量也对应规则的具体实现接口。这些常量和接口的对应关系如下:
CSSStyleRuleCSSImportRuleCSSMediaRuleCSSFontFaceRuleCSSPageRuleCSSNamespaceRuleCSSKeyframesRuleCSSKeyframeRuleCSSCounterStyleRuleCSSDocumentRuleCSSSupportsRuleCSSFontFeatureValuesRuleCSSViewportRule
An up-to-date informal list of constants can be found on the CSSWG Wiki.
语法
使用 WebIDL 语法格式进行描述。
interface CSSRule {
const unsigned short STYLE_RULE = 1;
const unsigned short CHARSET_RULE = 2;
const unsigned short IMPORT_RULE = 3;
const unsigned short MEDIA_RULE = 4;
const unsigned short FONT_FACE_RULE = 5;
const unsigned short PAGE_RULE = 6;
const unsigned short KEYFRAMES_RULE = 7;
const unsigned short KEYFRAME_RULE = 8;
const unsigned short NAMESPACE_RULE = 10;
const unsigned short COUNTER_STYLE_RULE = 11;
const unsigned short SUPPORTS_RULE = 12;
const unsigned short DOCUMENT_RULE = 13;
const unsigned short FONT_FEATURE_VALUES_RULE = 14;
const unsigned short VIEWPORT_RULE = 15;
const unsigned short REGION_STYLE_RULE = 16;
readonly attribute unsigned short type;
attribute DOMString cssText;
readonly attribute CSSRule? parentRule;
readonly attribute CSSStyleSheet? parentStyleSheet;
};
规范
| Specification |
|---|
| CSS Object Model (CSSOM)> # the-cssrule-interface> |
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