CSSRule
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2015.
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:
CSSStyleRule
CSSImportRule
CSSMediaRule
CSSFontFaceRule
CSSPageRule
CSSNamespaceRule
CSSKeyframesRule
CSSKeyframeRule
CSSCounterStyleRule
CSSDocumentRule
CSSSupportsRule
CSSFontFeatureValuesRule
CSSViewportRule
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 |
浏览器兼容性
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