为什么只设置line-height就可以实现文本垂直居中效果_html/css_WEB-ITnose
为什么只设置line-height就可以实现文本垂直居中效果:
在实际应用中，如果让单行文本在元素中垂直居中，可以将元素的高度和行高值设置为相同即可。
代码实例如下:
<!DOCTYPE html><html><head><meta charset=" utf-8"><meta name="author" content="http://www.softwhy.com/" /><title>蚂蚁部落</title><style type="text/css">div{ width:200px; height:50px; background:#CCC; line-height:50px; text-align:center;}</style></head><body><div>蚂蚁部落softwhy.com</div></body></html>上面的代码实现了我们的要求，div中的单行文本可以在div中垂直居中，使用的方式非常的简单，将height属性值和line-height属性值都设置为50px即可。其实在实际应用中，完全没有必要使用height属性，只用line-height就可以实现此功能，代码修改如下:
<!DOCTYPE html><html><head><meta charset=" utf-8"><meta name="author" content="http://www.softwhy.com/" /><title>蚂蚁部落</title><style type="text/css">div{ width:200px; background:#CCC; line-height:50px; text-align:center;}</style></head><body><div>蚂蚁部落softwhy.com</div></body></html>上面的代码虽然没看使用height属性，同样可以产生一个高度，并且可以使文字垂直居中。
看上去是不是有点奇怪，其实这是非常正常的表现，这是由于line-height属性产生的作用，下面做一下简单介绍。
在默认状态下，如果没有其他因素的干扰，文本会被一个content area box包裹，它的大小有字体的大小决定，这个时候content area box的大小和line box是相同的，当设置line-height属性之后，会有如下处理:
1.获取半行间距：半行间距=（line-height-content area box(也就是字体的大小)）/2。
2.然后把半行间距分别放置于content area box上下两侧，这样就获取了line box的高度尺寸。于是只要设置行高就可以产生一个高度，并且使文字居中。
特别说明:这里为了简略说明，故意省略一个inline box概念，具体可以参阅line-height属性深入介绍一章节。
原文地址是:http://www.softwhy.com/forum.php?mod=viewthread&tid=15915
更多内容可以参阅:http://www.softwhy.com/divcss/
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
AI Hentai Generator
Generate AI Hentai for free.
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
What is the purpose of the <datalist> element?
Mar 21, 2025 pm 12:33 PM
The article discusses the HTML <datalist> element, which enhances forms by providing autocomplete suggestions, improving user experience and reducing errors.Character count: 159
How do I use HTML5 form validation attributes to validate user input?
Mar 17, 2025 pm 12:27 PM
The article discusses using HTML5 form validation attributes like required, pattern, min, max, and length limits to validate user input directly in the browser.
What is the purpose of the <progress> element?
Mar 21, 2025 pm 12:34 PM
The article discusses the HTML <progress> element, its purpose, styling, and differences from the <meter> element. The main focus is on using <progress> for task completion and <meter> for stati
What is the purpose of the <iframe> tag? What are the security considerations when using it?
Mar 20, 2025 pm 06:05 PM
The article discusses the <iframe> tag's purpose in embedding external content into webpages, its common uses, security risks, and alternatives like object tags and APIs.
What is the purpose of the <meter> element?
Mar 21, 2025 pm 12:35 PM
The article discusses the HTML <meter> element, used for displaying scalar or fractional values within a range, and its common applications in web development. It differentiates <meter> from <progress> and ex
What are the best practices for cross-browser compatibility in HTML5?
Mar 17, 2025 pm 12:20 PM
Article discusses best practices for ensuring HTML5 cross-browser compatibility, focusing on feature detection, progressive enhancement, and testing methods.
What is the viewport meta tag? Why is it important for responsive design?
Mar 20, 2025 pm 05:56 PM
The article discusses the viewport meta tag, essential for responsive web design on mobile devices. It explains how proper use ensures optimal content scaling and user interaction, while misuse can lead to design and accessibility issues.
How do I use the HTML5 <time> element to represent dates and times semantically?
Mar 12, 2025 pm 04:05 PM
This article explains the HTML5 <time> element for semantic date/time representation. It emphasizes the importance of the datetime attribute for machine readability (ISO 8601 format) alongside human-readable text, boosting accessibilit
