我只是好奇为什么HTML中的<center>标记被弃用了。

<center>是一种通过将容器封装在<center>标签中来快速居中对齐文本和图像块的简单方法,现在我真的找不到任何更简单的方法了。

有人知道任何简单的方法如何居中“东西”(不是左边距:auto;margin-right:汽车;width),替换<center> ?还有,为什么它被弃用了?


当前回答

据W3Schools.com报道,

中心元素在HTML 4.01中已弃用,并且在XHTML 1.0 Strict DTD中不受支持。

HTML 4.01规范给出了弃用标记的原因:

CENTER元素完全等价于将align属性设置为“CENTER”来指定DIV元素。

其他回答

发人深思:文本-语音合成器使用<center>会做什么?

最不受欢迎的答案

已弃用的标记不一定是坏标记; 有处理表示逻辑的标签,center是其中之一; 中心标签与text-align:center的div不同; 事实上,你有另一种方法来做某事并不意味着它无效。

让我解释一下,因为这里有臭名昭著的反对者,他们会认为我在捍卫老式的HTML4或其他东西。不,我不是。但围绕中心的争论只是一场趋势之战,没有真正的理由抛弃一个有效的标签。

让我们来看看反对它的主要论点。

"It describes presentation, not semantics!" No. It describes a logical arrangement - and yes, it has a default appearance, just as other tags like <p> or <ul> do. But the point is the enclosed part's relation to its surroundings. Center says "this is something we separate by visually different positioning". "It's not valid" Yes it is. It's just deprecated, as in, could be removed later. For 15+ years now. And it's not going anywhere, apparently. There are major sites (including google.com) that use this tag because it's very readable and to the point - and those are the same reasons we like HTML5 tags for. "It's not supported in HTML5" It's one of the most widely supported tags, actually. MDN says "its use is discouraged since it could be removed at any time" - good point, but that day may never come, to quote a classic. Center was already deprecated in like 2004 or so - it's still here and still useful. "It's oldschool" Shoelaces are oldschool too. New methods don't invalidate the old. You want to feel progressive and modern: fine. But don't make it the law. "It's stupid / awkward / lame / tells a story about you" None of these. It's like a hammer: one tool for a specific job. There are other tools for the same job and other jobs for the same tool; but it was created to solve a certain problem and that problem is still around so we might as well just use a dedicated solution. "You shouldn't do this, because, CSS" Centering can absolutely be achieved by CSS but that's just one way, not the only one, let alone the only appropriate one. Anything that's supported, working and readable should be ok to use. Also, the same argument happened before flexboxes and CSS grids, which is funny because back then there was no CSS way to achieve what center did. No, text-align:center is not the same. No, margin:auto is not the same. Anyone who argued against center tags before flexbox simply didn't know enough about CSS.

TL; diana:

不使用<center>的唯一原因是人们会讨厌你。

CSS有一个text-align: center属性,因为这是一个纯粹的视觉东西,而不是语义,它应该归为CSS,而不是HTML。

对于文本和图像,您可以使用text-align:

<div style="text-align: center;">
    I'm centered.
</div>

HTML的目的是结构化数据,而不是控制布局。CSS用于控制布局。您还会发现许多设计人员出于同样的原因不愿意使用<table>进行布局。