css html
请看第一个代码<html><head><style type="text/css">h2.pos_left{position:relative;left:-20px}h2.pos_right{position:relative;left:20px}</style></head><body><h2 id="这是位于正常位置的标题">这是位于正常位置的标题</h2><h2 id="这个标题相对于其正常位置向左移动">这个标题相对于其正常位置向左移动</h2><h2 id="这个标题相对于其正常位置向右移动">这个标题相对于其正常位置向右移动</h2><p>相对定位会按照元素的原始位置对该元素进行移动。</p><p>样式 "left:-20px" 从元素的原始左侧位置减去 20 像素。</p><p>样式 "left:20px" 向元素的原始左侧位置增加 20 像素。</p></body></html>效果图： 如果把上面的代码改为
<html><head><style type="text/css">h2.pos_left{position:fixed;left:-20px}h2.pos_right{position:relative;left:20px}</style></head><body><h2 id="这是位于正常位置的标题">这是位于正常位置的标题</h2><h2 id="这个标题相对于其正常位置向左移动">这个标题相对于其正常位置向左移动</h2><h2 id="这个标题相对于其正常位置向右移动">这个标题相对于其正常位置向右移动</h2><p>相对定位会按照元素的原始位置对该元素进行移动。</p><p>样式 "left:-20px" 从元素的原始左侧位置减去 20 像素。</p><p>样式 "left:20px" 向元素的原始左侧位置增加 20 像素。</p></body></html>效果图就变成了 以上都是在chrome浏览器的调试图
高手解释为什么出现这种情况，谢谢了。
回复讨论(解决方案)
h2.pos_left{position:fixed;left:-20px} 这个是固定定位 ，属于绝对定位的一种，被固定定位的元素已经脱离了原来的文档流。固定定位 是相对于视窗窗口 定位的，所以 不管浏览器如何滚动，他都在相同位置
fixed 的包含块是视窗，不属于文档的流。
XML/HTML code?12345h2.pos_left{position:fixed;left:-20px}
这个是固定定位 ，属于绝对定位的一种，被固定定位的元素已经脱离了原来的文档流。固定定位 是相对于视窗窗口 定位的，所以 不管浏览器如何滚动，他都在相同位置
那为什么在正常位置下的两句话位置反过来了
fixed 的包含块是视窗，不属于文档的流。
在“这是位于正常位置的标题”下面两句话的位置倒过来了。
引用 2 楼 eazyc 的回复:fixed 的包含块是视窗，不属于文档的流。
在“这是位于正常位置的标题”下面两句话的位置倒过来了。
你 把浏览器 窗口 调小 ，出现滚动条 ，就会体会到 固定定位 是什么意思了
引用 4 楼 liulinisgood 的回复:引用 2 楼 eazyc 的回复:fixed 的包含块是视窗，不属于文档的流。
在“这是位于正常位置的标题”下面两句话的位置倒过来了。
你 把浏览器 窗口 调小 ，出现滚动条 ，就会体会到 固定定位 是什么意思了
嗯，试了一下，的确fixed是不会改变位置的，relative会随滚动条上下而动。
在浏览器最大化时候在两幅图中的两句话位置颠倒是不是因为relative需要和标准的相对位置固定，所以就在css 中fixed的段落之上了，理解是否有误（就是第二幅中的黑体三句话的顺序）
position: fixed;
这个是固定在可视区域，这个时候不占据文档流空间，就是“ ”设置固定定位后会把空间让出来，这个时候，下个H2元素就会占据pos_left的文档空间，就出现了你看到的现象
楼主看下
http://www.w3school.com.cn/css/pr_class_position.asp
生成绝对定位的元素，相对于浏览器窗口进行定位。
另外建议楼主 写css加上 nbsp;HTML>
ie低版本不支持fixed，需要另作处理
What is the difference between an HTML tag and an HTML attribute?May 14, 2025 am 12:01 AMHTMLtagsdefinethestructureofawebpage,whileattributesaddfunctionalityanddetails.1)Tagslike,,andoutlinethecontent'splacement.2)Attributessuchassrc,class,andstyleenhancetagsbyspecifyingimagesources,styling,andmore,improvingfunctionalityandappearance.
The Future of HTML: Evolution and TrendsMay 13, 2025 am 12:01 AMThe future of HTML will develop in a more semantic, functional and modular direction. 1) Semanticization will make the tag describe the content more clearly, improving SEO and barrier-free access. 2) Functionalization will introduce new elements and attributes to meet user needs. 3) Modularity will support component development and improve code reusability.
Why are HTML attributes important for web development?May 12, 2025 am 12:01 AMHTMLattributesarecrucialinwebdevelopmentforcontrollingbehavior,appearance,andfunctionality.Theyenhanceinteractivity,accessibility,andSEO.Forexample,thesrcattributeintagsimpactsSEO,whileonclickintagsaddsinteractivity.Touseattributeseffectively:1)Usese
What is the purpose of the alt attribute? Why is it important?May 11, 2025 am 12:01 AMThe alt attribute is an important part of the tag in HTML and is used to provide alternative text for images. 1. When the image cannot be loaded, the text in the alt attribute will be displayed to improve the user experience. 2. Screen readers use the alt attribute to help visually impaired users understand the content of the picture. 3. Search engines index text in the alt attribute to improve the SEO ranking of web pages.
HTML, CSS, and JavaScript: Examples and Practical ApplicationsMay 09, 2025 am 12:01 AMThe roles of HTML, CSS and JavaScript in web development are: 1. HTML is used to build web page structure; 2. CSS is used to beautify the appearance of web pages; 3. JavaScript is used to achieve dynamic interaction. Through tags, styles and scripts, these three together build the core functions of modern web pages.
How do you set the lang attribute on the tag? Why is this important?May 08, 2025 am 12:03 AMSetting the lang attributes of a tag is a key step in optimizing web accessibility and SEO. 1) Set the lang attribute in the tag, such as. 2) In multilingual content, set lang attributes for different language parts, such as. 3) Use language codes that comply with ISO639-1 standards, such as "en", "fr", "zh", etc. Correctly setting the lang attribute can improve the accessibility of web pages and search engine rankings.
What is the purpose of HTML attributes?May 07, 2025 am 12:01 AMHTMLattributesareessentialforenhancingwebelements'functionalityandappearance.Theyaddinformationtodefinebehavior,appearance,andinteraction,makingwebsitesinteractive,responsive,andvisuallyappealing.Attributeslikesrc,href,class,type,anddisabledtransform
How do you create a list in HTML?May 06, 2025 am 12:01 AMTocreatealistinHTML,useforunorderedlistsandfororderedlists:1)Forunorderedlists,wrapitemsinanduseforeachitem,renderingasabulletedlist.2)Fororderedlists,useandfornumberedlists,customizablewiththetypeattributefordifferentnumberingstyles.
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
EditPlus Chinese cracked version
Small size, syntax highlighting, does not support code prompt function
SublimeText3 English version
Recommended: Win version, supports code prompts!
MantisBT
Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.
SublimeText3 Linux new version
SublimeText3 Linux latest version
SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.
