CSSRuleList

A CSSRuleList is an (indirect-modify only) array-like object containing an ordered collection of CSSRule 对象。

描述

CSSRule can be accessed as rules .item( index ), or simply rules [ index ] , where rules is an object implementing the CSSRuleList interface (such as CSSStylesheet .cssRules ), and index is the 0-based index of the rule, in the order as it appears in the style sheet CSS. The number of rules in the list is rules .length .

Note that being indirect-modify ( changeable but only having read-methods), rules are NOT added or removed from the list directly, but instead here, only via its parent stylesheet. In fact, .insertRule() and .deleteRule() are not even methods of CSSRuleList, but only of CSSStyleSheet . If however, for some reason the list does need to be modified but has no parent stylesheet (perhaps being a livecopy of a list that does), it cannot just be assigned one (as it has no such property ), and neither can it be assigned to one (as stylesheet.css Rules is 只读 ), but it must unfortunately be inserted into one, rule by rule, and unless combining lists, after any existing list therein is deleted, rule by rule.

范例

// get the first style sheet’s first rule
var first_rule = document.styleSheets[0].cssRules[0];
					

另请参阅

CSSRuleList implementations

There are multiple properties in the CSSOM that will return a CSSRuleList . They are:

规范

规范 状态 Comment
CSS Object Model (CSSOM)
The definition of 'CSSRuleList' in that specification.
工作草案

浏览器兼容性

更新 GitHub 上的兼容性数据
Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet
CSSRuleList Chrome 1 Edge ≤18 Firefox 1 IE ? Opera Yes Safari Yes WebView Android Yes Chrome Android Yes Firefox Android 4 Opera Android Yes Safari iOS Yes Samsung Internet Android Yes
item Chrome 1 Edge 12 Firefox 1 IE ? Opera Yes Safari Yes WebView Android Yes Chrome Android Yes Firefox Android 4 Opera Android Yes Safari iOS Yes Samsung Internet Android Yes
length Chrome 1 Edge 12 Firefox 25 IE ? Opera Yes Safari Yes WebView Android Yes Chrome Android Yes Firefox Android 25 Opera Android Yes Safari iOS Yes Samsung Internet Android Yes

图例

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