bootstrap flex不将内容居中

Question

bootstrap flex不将内容居中

<div class="d-flex flex-row bd-highlight mb-3">
  <div class="p-2 bd-highlight text-left"><i class="fa fa-chevron-left" aria-hidden="true"></i></div>
  <div class="p-2 bd-highlight text-muted text-center justify-content-center" style="text-transform: uppercase;">comments</div>
  <div class="p-2 bd-highlight">Flex item 3</div>
</div>

我使用的是bootstrap 4，不知何故text-center justify-content-center类不能工作，有人能帮我吗？

Answer 1

Bootstrap4 justify classes需要应用于行(使用d-flex类)，而不是列。

将justify-content-center移到父级，使元素按预期居中。

​

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">
<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>

<div class="d-flex flex-row bd-highlight mb-3 justify-content-center">
  <div class="p-2 bd-highlight text-left"><i class="fa fa-chevron-left" aria-hidden="true"></i></div>
  <div class="p-2 bd-highlight text-muted" style="text-transform: uppercase;">comments</div>
  <div class="p-2 bd-highlight">Flex item 3</div>
</div>

​

请注意，这将使所有元素居中。如果你正在寻找一个“左-中-右”的布局(这样只有中间的元素居中)，那么你想要justify-content-between：

​

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">
<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>

<div class="d-flex flex-row bd-highlight mb-3 justify-content-between">
  <div class="p-2 bd-highlight text-left"><i class="fa fa-chevron-left" aria-hidden="true"></i></div>
  <div class="p-2 bd-highlight text-muted" style="text-transform: uppercase;">comments</div>
  <div class="p-2 bd-highlight">Flex item 3</div>
</div>

​