CSS选择符优先级引起的样式失效_html/css_WEB-ITnose
选择符优先级带来的样式失效:
由于CSS选择符优先级可能引起某些样式失效,这个问题初学者可能会碰上,但是往往并不容易发现。
代码实例:
<!DOCTYPE html><html><head><meta charset="utf-8"><meta name="author" content="http://www.51texiao.cn/" /><title>蚂蚁部落</title><style type="text/css">.mydiv{color:green;}</style></head><body><div class="mydiv"> <ul> <li>蚂蚁部落</li> <li>div+css专区</li> <li>HTML专区</li> </ul></div></body></html>
以上代码可以将li元素中的所有文字设置为绿色。这个时候可能需求变了,要将第一个li元素作为标题,需要改变一下它的元素。
代码如下:
<!DOCTYPE html><html><head><meta charset="utf-8"><meta name="author" content="http://www.51texiao.cn/" /><title>蚂蚁部落</title><style type="text/css">.mydiv li{color:green;}.myli{color:blue;}</style></head><body><div class="mydiv"> <ul> <li class="myli">蚂蚁部落</li> <li>div+css专区</li> <li>HTML专区</li> </ul></div></body></html>
尽管给第一个li元素单独设置了class类,并且规定了新的颜色,但是并没有生效。这就是由选择符优先级导致的。
只要将CSS代码做如下修改即可:
.mydiv li{color:green;} .mydiv .myli{color:blue;}
如需了解选择符优先级规则,可以参阅CSS选择符优先级一章节。
原文地址是:http://www.51texiao.cn/div_cssjiaocheng/2015/0519/1894.html
最为原始地址是:http://www.softwhy.com/forum.php?mod=viewthread&tid=4701

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics











HTML is suitable for beginners because it is simple and easy to learn and can quickly see results. 1) The learning curve of HTML is smooth and easy to get started. 2) Just master the basic tags to start creating web pages. 3) High flexibility and can be used in combination with CSS and JavaScript. 4) Rich learning resources and modern tools support the learning process.

WebdevelopmentreliesonHTML,CSS,andJavaScript:1)HTMLstructurescontent,2)CSSstylesit,and3)JavaScriptaddsinteractivity,formingthebasisofmodernwebexperiences.

HTML defines the web structure, CSS is responsible for style and layout, and JavaScript gives dynamic interaction. The three perform their duties in web development and jointly build a colorful website.

AnexampleofastartingtaginHTMLis,whichbeginsaparagraph.StartingtagsareessentialinHTMLastheyinitiateelements,definetheirtypes,andarecrucialforstructuringwebpagesandconstructingtheDOM.

HTML, CSS and JavaScript are the three pillars of web development. 1. HTML defines the web page structure and uses tags such as, etc. 2. CSS controls the web page style, using selectors and attributes such as color, font-size, etc. 3. JavaScript realizes dynamic effects and interaction, through event monitoring and DOM operations.

The roles of HTML, CSS and JavaScript in web development are: 1. HTML defines the web page structure, 2. CSS controls the web page style, and 3. JavaScript adds dynamic behavior. Together, they build the framework, aesthetics and interactivity of modern websites.

The future of HTML is full of infinite possibilities. 1) New features and standards will include more semantic tags and the popularity of WebComponents. 2) The web design trend will continue to develop towards responsive and accessible design. 3) Performance optimization will improve the user experience through responsive image loading and lazy loading technologies.

The future trends of HTML are semantics and web components, the future trends of CSS are CSS-in-JS and CSSHoudini, and the future trends of JavaScript are WebAssembly and Serverless. 1. HTML semantics improve accessibility and SEO effects, and Web components improve development efficiency, but attention should be paid to browser compatibility. 2. CSS-in-JS enhances style management flexibility but may increase file size. CSSHoudini allows direct operation of CSS rendering. 3.WebAssembly optimizes browser application performance but has a steep learning curve, and Serverless simplifies development but requires optimization of cold start problems.
