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
介绍IE8的CSS hack
CSS教程:解析CSS列表样式属性list-style
CSS教程:CSS页面布局的技巧
对付CSS兼容问题的十个超级技巧
CSS3教程:box-sizing属性
CSS教程:29个特殊的CSS导航技术
CSS教程:CSS控制浏览器滚动条的源代码
DIV+CSS制作网页之如何设置z-index
制作网页表单的标签和输入区
网页文件上传表单的制作
网页表单标签水平右对齐更适合中文网站
CSS在各个网页版邮箱中的支持情况
彻底弄清楚haslayout概念
CSS教程:滑动门与选项卡
总结关于网页表单反馈的一些问题
CSS Sprite操作:用CSS处理圆角
网站栅格化设计
减少网站加载时间:CSS Sprites
通过CSS实例实现清除浮动
CSS教程:实例讲解定位Position

No. « 56 57 58 59 »

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: 236 ::
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;}