当前位置: 首页 > 图文教程 > 网页制作 > CSS样式表 > 英文教程:五种CSS选择器类型

CSS样式表
CSS教程:表格不被撑开的解决办法
网页制作教程:简单总结CSS的基础属性
css文件不能被正常载入的问题解决方法
css模块化的思想让后期维护变得简单
凹陷文字 推荐
CSS 实用实例(推荐)
标准化：表格
一个导航条布局的简单写法
CSS实现阴影文字效果
全面考察“禁用浏览器后退”
让2个DIV居中并排显示
从gb到utf-8
以前写的两个CSS树形菜单
何为“VML”、VML的基底知识
Meta标签详解
学习标准：笔记
多中语言实现判断客户访问用得是那个域名 然后转到对应的目录
解决IE5/IE5.5/IE6/FF的兼容性问题：CSS
CSS网页布局入门教程9：用CSS设计网站导航：横向导航
web标准知识：从p开始，循序渐进

No. « 72 73 74 75 »

技术文章搜索

关键字

CSS样式表 中的 英文教程:五种CSS选择器类型

出处:互联网   整理: 软晨网（RuanChen.com）   发布: 2009-09-11   浏览: 213 ::
收藏到网摘: n/a


                         英文教程:五种CSS选择器类型.              CSScommandsareusuallygroupedinthecurlybracestomakeasetofrules.FollowingarethevariouswaysavailabletoattachthesesetofruleswithHTMLcode.
Selector(insimplewords)meanshowyounamethesesetofrules.
1CLASSSelectORS
ClassselectorsisthesimplestformofselectorswhereyouassignyourownmeaningfulnametothesetofCSSrules.Tocreateaclassselectoryousimplyneedtowritenameoftheclassfollowedbyaperiod.
(Aclassnamecannotstartwithanumberorasymbolasitisnotsupportedbyvariousbrowsers.)
Forexample,
p.big{font-weight:bold;font-size:12px;}
.center{text-align:center;}
AndthisHTML:
<pclass="big">Thisparagraphwillberenderedbold.www.ruanchen.com</p>
Youcanapplymorethanoneclasstoagivenelement.
AndthisHTML:
<pclass="centerbig">Thisparagraphwillberenderedbold.</p>
Intheaboveexample.bigand.centerarenameofCSSclassesandtheseclassesareappliedtoPtaginHTML.
IfclassnameisfollowedbyHTMLelementinyourCSScodelikep.biginaboveexampleitmeansthatthisclasswillworkonPtagonly.
OtherwiseyoucanapplytheCSSclassonanyelement.
It’sagoodpracticetoaddHTMLelementbeforeclassnameinCSSifyouarewritingCSSrulesforaparticularelement(ItaddsmoreclaritytoCSScode.
2IDSelectORS
IDselectorsworklikeclassselectors,exceptthattheycanonlybeusedononeelementperpagebecausetheyworkwithIDofthehtmlelement.TheidselectorisdefinedasidoftheHTMLelementfollowedbya#symbol.
Forexample,
p#navigation{width:12em;color:#666;font-weight:bold;}
AndthisHTML:
<pid="navigation">Thisparagraphwillberenderedbold.www.ruanchen.com</p>
AsagoodpracticeIDselectorsmustbeusedifyouarewritingtheCSScodeforasingleHTMLelementonly.IDselectorsarewellsupportedacrossstandards-compliantbrowsers.
3TAGSelectOR
TagselectorisanothersimplemethodofCSSrulesimplementation.YoucanusethisselectortoredefinetherulesforaparticularHTMLelement.
Forexample:
p{color:#999;font-weight:bold;}
IntheaboveexampleCSScodewillbeautomaticallyappliedoneveryptag.
4DESCENDENTSelectORS
Descendentselectorsspecifythatstylesshouldonlybeappliedwhentheelementinquestionisadescendent(forexample,achild,oragrandchild)ofanotherelement.
Forexample,
h3em{color:white;background-color:black;}
AndthisHTML:
<h3>Thisis<em>emphasized</em>www.ruanchen.com</h3>
Intheaboveexampleemisdescendentofh3element.Abovecssrulewillautomaticallybeappliedonallemelementsinsideh3elementintheHTMLcode.Descendentselectorsarewellsupportedacrossstandards-compliantbrowsers.
5GROUPINGSelectORS
Youcanalsospecifythesamesetofrulesformorethanoneselctor,likethis:
p,h1,h2{text-align:left;}
Justplaceacommabetweeneachone.
Youcanevengetmorecomplex,andgroupmultipleclassandidselectors:
p.navigation,h1#title{font-weight:bold;}