第一種:css
<style type="text/css"> .div1 { width: 100px; height: 100px; border: 1px solid #000000; position: relative;
} .div2 { width: 40px; height: 40px; background-color: red; position: absolute; margin: auto; top: 0; left: 0; right: 0; bottom: 0;
}
</style>
<div class="div1">
<div class="div2 ">
</div>
</div>
效果圖:css3
第二種:佈局
<style type="text/css"> .div1 { width: 100px; height: 100px; border: 1px solid #000000; display: table-cell; vertical-align: middle;
} .div2 { width: 40px; height: 40px; background-color: red; margin: auto;
}
</style>
<div class="div1">
<div class="div2">
</div>
</div>
效果:flex
第三種:flexbox
<style type="text/css"> .div1 { width: 100px; height: 100px; border: 1px solid #000000; display: flex;
/*!*flex-direction: column;*!可寫可不寫*/ justify-content: center; align-items: center;
} .div2 { height: 40px; width: 40px; background-color: red;
}
</style>
<div class="div1 ">
<div class="div2 ">
</div>
</div>
效果:spa
第四種:code
<style type="text/css"> .div1 { width: 100px; height: 100px; border: 1px solid #000000; position: relative;
} .div2 { height: 40px; width: 40px; background-color: red; position: absolute; top: 50%; left: 50%; -ms-transform: translate(-50%, -50%); -moz-transform: translate(-50%, -50%); -o-transform: translate(-50%, -50%); transform: translate(-50%, -50%);
}
</style>
<div class="div1 ">
<div class="div2 ">
</div>
</div>
效果圖:orm