深入理解CSS3结构伪类选择器

Deep Understanding of CSS3 Structural Pseudo-Classes Selectors

本文从结构伪类与类选择器的比较、结构伪类与文档树的关系、结构伪类的功能与应用等三个层面,深入阐述了结构伪类的作用,结构伪类所表示的文档树结构,结构伪类通过位置索引定位子元素的机制。通过将定位子元素的结构伪类分为带参数和不带参数两类,深入论述了带参数结构伪类的参数模式、典型应用及与不带参数结构伪类的对应关系。

The article describes deeply the function of the structural pseudo-classes,the document tree structure represented by structural pseudo-classes and structural pseudo-classes’mechanism of positioning sub-element by means of position index from the aspects of the comparison of the structural pseudo-classes and class selectors,the relationship of the structural pseudo-classes and the document tree as well as the functions and applications of the structural pseudoclasses.The article discusses in detail the parameter model and typical application with parameter structural pseudo-class,the corresponding relations between structural pseudo-class with and without parameters by dividing the structural pseudo-class of positioning sub-element into two classes with and without parameters.