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 CSSStyleSheetcssRules 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 CSSRuletype 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:

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

BCD tables only load in the browser

参见