另一个答案是这样的。

<div id="container"> 
    <div id="centered"> </div>
</div>

还有css:

#container {
    height: 400px;
    width: 400px;
    background-color: lightblue;
    text-align: center;
}

#container:before {
    height: 100%;
    content: '';
    display: inline-block;
    vertical-align: middle;
}

#centered {
    width: 100px;
    height: 100px;
    background-color: blue;
    display: inline-block;
    vertical-align: middle;
    margin: 0 auto;
}

我认为有两种方法使div中心对齐通过CSS。

.middleDiv {
    position : absolute;    
    width    : 200px;
    height   : 200px;
    left     : 50%;
    top      : 50%;
    margin-left : -100px; /* half of the width  */
    margin-top  : -100px; /* half of the height */
}

这是最简单最好的方法。演示请访问以下链接:

http://w3webpro.blogspot.in/2013/07/how-to-make-div-horizontally-and.html

实际上有一个解决方案，使用css3，它可以垂直居中一个未知高度的div。诀窍是将div向下移动50%，然后使用transformmy将其移回中间。唯一的前提条件是要居中的元素有一个父元素。例子:

<div class="parent">
    <div class="center-me">
        Text, images, whatever suits you.
    </div>
</div>

.parent { 
    /* height can be whatever you want, also auto if you want a child 
       div to be responsible for the sizing */ 
    height: 200px;
}

.center-me { 
    position: relative;
    top: 50%;
    transform: translateY(-50%);
    /* prefixes needed for cross-browser support */
    -ms-transform: translateY(-50%);
    -webkit-transform: translateY(-50%);
}

所有主流浏览器和ie9及以上版本都支持(别担心ie8，因为它在今年秋天和winxp一起死了。感谢上帝)。

JS小提琴演示

是浏览器支持的，使用翻译功能强大。

position: absolute;
background-color: red;

width: 70%;     
height: 30%; 

/* The translate % is relative to the size of the div and not the container*/ 
/* 21.42% = ( (100%-70%/2) / 0.7 ) */
/* 116.666% = ( (100%-30%/2) / 0.3 ) */
transform: translate3d( 21.42%, 116.666%, 0);

我会使用translate:

首先，将div的左上角定位在页面的中心(使用位置:固定;上图:50%;左:50%)。然后，translate将其向上移动50%的div高度，使其在页面上垂直居中。最后，translate还将div向右移动50%的宽度，使其水平居中。

实际上，我认为这个方法比其他许多方法更好，因为它不需要对父元素进行任何更改。

在某些情况下，Translate比translate3d更好，因为它被更多的浏览器支持。https://caniuse.com/#feat=transforms2d

综上所述，所有版本的Chrome、Firefox 3.5+、Opera 11.5+、所有版本的Safari、IE 9+和Edge都支持此方法。

.centered { position: fixed; top: 50%; left: 50%; transform: translate(-50%, -50%); -webkit-transform: translate(-50%, -50%); -moz-transform: translate(-50%, -50%); -o-transform: translate(-50%, -50%); -ms-transform: translate(-50%, -50%); font-size: 20px; background-color: cyan; border: darkgreen 5px solid; padding: 5px; z-index: 100; } table { position: absolute; top: 0; left: 0; } td { position: relative; top: 0; left: 0; } <table> <tr> <td> <div class="centered">This div<br />is centered</div> <p> Lorem ipsum dolor sit amet, nam sint laoreet at, his ne sumo causae, simul decore deterruisset ne mel. Exerci atomorum est ut. At choro vituperatoribus usu. Dico epicurei persequeris quo ex, ea ius zril phaedrum eloquentiam, duo in aperiam admodum fuisset. No quidam consequuntur usu, in amet hinc simul eos. Ex soleat meliore percipitur mea, nihil omittam salutandi ut eos. Mea et impedit facilisi pertinax, ea viris graeci fierent pri, te sonet intellegebat his. Vis denique albucius instructior ad, ex eum iudicabit elaboraret. Sit ea intellegam liberavisse. Nusquam quaestio maiestatis ut qui, eam decore altera te. Unum cibo aliquip ut qui, te mea doming prompta. Ex rebum interesset nam, te nam zril suscipit, qui suavitate explicari appellantur te. Usu brute corpora mandamus eu. Dicit soluta his eu. In sint consequat sed, quo ea tota petentium. Adhuc prompta splendide mel ad, soluta delenit nec cu. </p> </td> <td> <p> Lorem ipsum dolor sit amet, dico choro recteque te cum, ex omnesque consectetuer sed, alii esse utinam et has. An qualisque democritum usu. Ea has habeo labores, laoreet intellegat te mea. Eius equidem inermis vel ne. Ne eum sonet labitur, nec id natum munere. Primis graecis est cu, quis dictas eu mea, eu quem offendit forensibus nec. Id animal mandamus his, vis in sonet tempor luptatum. Ne civibus oporteat comprehensam vix, per facete discere atomorum eu. Mucius probatus volutpat sit an, sumo nominavi democritum eam ut. Ea sit choro graece debitis, per ex verear voluptua epicurei. Id eum wisi dicat, ea sit velit doming cotidieque, eu sea amet delenit. Populo tacimates dissentiunt has cu. Has wisi hendrerit at, et quo doming putent docendi. Ea nibh vide omnium usu. </p> </td> </tr> </table>

但是，请注意，该方法使该div在页面滚动时停留在一个位置。这可能是你想要的，但如果不是，还有另一种方法。

现在，如果我们尝试相同的CSS，但将位置设置为绝对，它将在最后一个具有绝对位置的父元素的中心。

.centered { position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%); -webkit-transform: translate(-50%, -50%); -moz-transform: translate(-50%, -50%); -o-transform: translate(-50%, -50%); -ms-transform: translate(-50%, -50%); font-size: 20px; background-color: cyan; border: darkgreen 5px solid; padding: 5px; z-index: 100; } table { position: absolute; top: 0; left: 0; } td { position: relative; top: 0; left: 0; } <table> <tr> <td> <div class="centered">This div<br />is centered</div> <p> Lorem ipsum dolor sit amet, nam sint laoreet at, his ne sumo causae, simul decore deterruisset ne mel. Exerci atomorum est ut. At choro vituperatoribus usu. Dico epicurei persequeris quo ex, ea ius zril phaedrum eloquentiam, duo in aperiam admodum fuisset. No quidam consequuntur usu, in amet hinc simul eos. Ex soleat meliore percipitur mea, nihil omittam salutandi ut eos. Mea et impedit facilisi pertinax, ea viris graeci fierent pri, te sonet intellegebat his. Vis denique albucius instructior ad, ex eum iudicabit elaboraret. Sit ea intellegam liberavisse. Nusquam quaestio maiestatis ut qui, eam decore altera te. Unum cibo aliquip ut qui, te mea doming prompta. Ex rebum interesset nam, te nam zril suscipit, qui suavitate explicari appellantur te. Usu brute corpora mandamus eu. Dicit soluta his eu. In sint consequat sed, quo ea tota petentium. Adhuc prompta splendide mel ad, soluta delenit nec cu. </p> </td> <td> <p> Lorem ipsum dolor sit amet, dico choro recteque te cum, ex omnesque consectetuer sed, alii esse utinam et has. An qualisque democritum usu. Ea has habeo labores, laoreet intellegat te mea. Eius equidem inermis vel ne. Ne eum sonet labitur, nec id natum munere. Primis graecis est cu, quis dictas eu mea, eu quem offendit forensibus nec. Id animal mandamus his, vis in sonet tempor luptatum. Ne civibus oporteat comprehensam vix, per facete discere atomorum eu. Mucius probatus volutpat sit an, sumo nominavi democritum eam ut. Ea sit choro graece debitis, per ex verear voluptua epicurei. Id eum wisi dicat, ea sit velit doming cotidieque, eu sea amet delenit. Populo tacimates dissentiunt has cu. Has wisi hendrerit at, et quo doming putent docendi. Ea nibh vide omnium usu. </p> </td> </tr> </table>

我在看Laravel的视图文件，注意到他们完美地将文本居中。我立刻想起了这个问题。 他们是这样做的:

<html>
<head>
    <title>Laravel</title>

    <!--<link href='//fonts.googleapis.com/css?family=Lato:100' rel='stylesheet' type='text/css'>-->

    <style>
        .container {
            margin: 0;
            padding: 0;
            width: 100%;
            height: 100%;
            display: table;

        }

        .inside {
            text-align: center;
            display: table-cell;
            vertical-align: middle;
        }


    </style>
</head>
<body>
    <div class="container">
            <div class="inside">This text is centered</div>
    </div>
</body>

结果如下所示: