Columns(列布局)
借助我们的 flexbox 网格系统,了解如何使用一些对齐、排序和偏移选项来修改列。另外,了解如何使用列类来管理非网格元素的宽度。
他们是如何工作的
-
列建立在网格的 flexbox 架构之上。Flexbox 意味着我们可以选择在行级别更改单个列和修改列组。您可以选择列如何增长、收缩或以其他方式改变。
-
在构建网格布局时,所有内容都放在列中。Bootstrap 网格的层次结构从容器到行到列到您的内容。在极少数情况下,您可以将内容和列结合起来,但请注意可能会产生意想不到的后果。
-
Bootstrap 包括用于创建快速、响应式布局的预定义类。每个网格层有六个断点和十几个列,我们已经为您构建了几十个类来创建您想要的布局。如果你愿意,可以通过 Sass 禁用它。
对齐
使用 flexbox 对齐实用程序来垂直和水平对齐列。
垂直对齐
align-items-*
更改任何响应类的垂直对齐方式。
<div class="container text-center">
<div class="row align-items-start">
<div class="col">
One of three columns
</div>
<div class="col">
One of three columns
</div>
<div class="col">
One of three columns
</div>
</div>
</div>
<div class="container text-center">
<div class="row align-items-center">
<div class="col">
One of three columns
</div>
<div class="col">
One of three columns
</div>
<div class="col">
One of three columns
</div>
</div>
</div>
<div class="container text-center">
<div class="row align-items-end">
<div class="col">
One of three columns
</div>
<div class="col">
One of three columns
</div>
<div class="col">
One of three columns
</div>
</div>
</div>
或者,使用任何.align-self-*
响应类单独更改每一列的对齐方式。
<div class="container text-center">
<div class="row">
<div class="col align-self-start">
One of three columns
</div>
<div class="col align-self-center">
One of three columns
</div>
<div class="col align-self-end">
One of three columns
</div>
</div>
</div>
水平对齐
<div class="container text-center">
<div class="row justify-content-start">
<div class="col-4">
One of two columns
</div>
<div class="col-4">
One of two columns
</div>
</div>
<div class="row justify-content-center">
<div class="col-4">
One of two columns
</div>
<div class="col-4">
One of two columns
</div>
</div>
<div class="row justify-content-end">
<div class="col-4">
One of two columns
</div>
<div class="col-4">
One of two columns
</div>
</div>
<div class="row justify-content-around">
<div class="col-4">
One of two columns
</div>
<div class="col-4">
One of two columns
</div>
</div>
<div class="row justify-content-between">
<div class="col-4">
One of two columns
</div>
<div class="col-4">
One of two columns
</div>
</div>
<div class="row justify-content-evenly">
<div class="col-4">
One of two columns
</div>
<div class="col-4">
One of two columns
</div>
</div>
</div>
列包装
如果超过 12 列放置在一行中,每组额外的列将作为一个单元换行。
Since 9 + 4 = 13 > 12, this 4-column-wide div gets wrapped onto a new line as one contiguous unit.
Subsequent columns continue along the new line.
<div class="container">
<div class="row">
<div class="col-9">.col-9</div>
<div class="col-4">.col-4<br>Since 9 + 4 = 13 > 12, this 4-column-wide div gets wrapped onto a new line as one contiguous unit.</div>
<div class="col-6">.col-6<br>Subsequent columns continue along the new line.</div>
</div>
</div>
分栏符
在 flexbox 中将列换行需要一个小技巧:添加一个width: 100%
元素,在任何你想将列换行的地方。通常这是通过多个.row
来完成的,但并不是每个实现方法都能解决这个问题。
<div class="container text-center">
<div class="row">
<div class="col-6 col-sm-3">.col-6 .col-sm-3</div>
<div class="col-6 col-sm-3">.col-6 .col-sm-3</div>
<!-- Force next columns to break to new line -->
<div class="w-100"></div>
<div class="col-6 col-sm-3">.col-6 .col-sm-3</div>
<div class="col-6 col-sm-3">.col-6 .col-sm-3</div>
</div>
</div>
您还可以使用我们的响应式显示实用程序在特定断点处应用此中断。
<div class="container text-center">
<div class="row">
<div class="col-6 col-sm-4">.col-6 .col-sm-4</div>
<div class="col-6 col-sm-4">.col-6 .col-sm-4</div>
<!-- Force next columns to break to new line at md breakpoint and up -->
<div class="w-100 d-none d-md-block"></div>
<div class="col-6 col-sm-4">.col-6 .col-sm-4</div>
<div class="col-6 col-sm-4">.col-6 .col-sm-4</div>
</div>
</div>
重新排序
排序类
使用.order-
类来控制内容的视觉顺序。这些类是响应式的,因此您可以设置order
断点(例如,.order-1.order-md-2
)。包括对1
至5
所有六个网格层的支持。如果你需要更多.order-*
的类,你可以通过 Sass 变量修改默认数量。
<div class="container text-center">
<div class="row">
<div class="col">
First in DOM, no order applied
</div>
<div class="col order-5">
Second in DOM, with a larger order
</div>
<div class="col order-1">
Third in DOM, with an order of 1
</div>
</div>
</div>
还有响应式的.order-first
和.order-last
类分别通过应用order: -1
和order: 6
来改变元素的order
。这些类也可以根据需要与编号类.order-*
混合使用。
<div class="container text-center">
<div class="row">
<div class="col order-last">
First in DOM, ordered last
</div>
<div class="col">
Second in DOM, unordered
</div>
<div class="col order-first">
Third in DOM, ordered first
</div>
</div>
</div>
偏移列
您可以通过两种方式偏移网格列:我们的响应式.offset-
网格类和我们的边距实用程序。网格类的大小与列匹配,而边距对于偏移宽度可变的快速布局更有用。
偏移类
使用类将列向右移动.offset-md-*
。这些类逐列增加一列的左边距*
。例如,.offset-md-4
移动.col-md-4
四列。
<div class="container text-center">
<div class="row">
<div class="col-md-4">.col-md-4</div>
<div class="col-md-4 offset-md-4">.col-md-4 .offset-md-4</div>
</div>
<div class="row">
<div class="col-md-3 offset-md-3">.col-md-3 .offset-md-3</div>
<div class="col-md-3 offset-md-3">.col-md-3 .offset-md-3</div>
</div>
<div class="row">
<div class="col-md-6 offset-md-3">.col-md-6 .offset-md-3</div>
</div>
</div>
除了在响应断点处清除列外,您可能还需要重置偏移量。请参阅网格示例中的实际操作。
<div class="container text-center">
<div class="row">
<div class="col-sm-5 col-md-6">.col-sm-5 .col-md-6</div>
<div class="col-sm-5 offset-sm-2 col-md-6 offset-md-0">.col-sm-5 .offset-sm-2 .col-md-6 .offset-md-0</div>
</div>
<div class="row">
<div class="col-sm-6 col-md-5 col-lg-6">.col-sm-6 .col-md-5 .col-lg-6</div>
<div class="col-sm-6 col-md-5 offset-md-2 col-lg-6 offset-lg-0">.col-sm-6 .col-md-5 .offset-md-2 .col-lg-6 .offset-lg-0</div>
</div>
</div>
边距实用程序
在 v4 中迁移到 flexbox 后,您可以使用边距实用程序,例如.me-auto
强制兄弟列彼此远离。
<div class="container text-center">
<div class="row">
<div class="col-md-4">.col-md-4</div>
<div class="col-md-4 ms-auto">.col-md-4 .ms-auto</div>
</div>
<div class="row">
<div class="col-md-3 ms-md-auto">.col-md-3 .ms-md-auto</div>
<div class="col-md-3 ms-md-auto">.col-md-3 .ms-md-auto</div>
</div>
<div class="row">
<div class="col-auto me-auto">.col-auto .me-auto</div>
<div class="col-auto">.col-auto</div>
</div>
</div>
独立列类
这些.col-*
类也可以在.row
外部使用,以赋予元素特定的宽度。每当列类用作一行的非直接子级时,填充将被省略。
<div class="col-3 p-3 mb-2">
.col-3: width of 25%
</div>
<div class="col-sm-9 p-3">
.col-sm-9: width of 75% above sm breakpoint
</div>
这些类可以与实用程序一起使用来创建响应式浮动图像。如果文本较短,请确保将内容包装在包装器.clearfix
中以清除浮动。
A paragraph of placeholder text. We're using it here to show the use of the clearfix class. We're adding quite a few meaningless phrases here to demonstrate how the columns interact here with the floated image.
As you can see the paragraphs gracefully wrap around the floated image. Now imagine how this would look with some actual content in here, rather than just this boring placeholder text that goes on and on, but actually conveys no tangible information at. It simply takes up space and should not really be read.
And yet, here you are, still persevering in reading this placeholder text, hoping for some more insights, or some hidden easter egg of content. A joke, perhaps. Unfortunately, there's none of that here.
<div class="clearfix">
<img src="..." class="col-md-6 float-md-end mb-3 ms-md-3" alt="...">
<p>
A paragraph of placeholder text. We're using it here to show the use of the clearfix class. We're adding quite a few meaningless phrases here to demonstrate how the columns interact here with the floated image.
</p>
<p>
As you can see the paragraphs gracefully wrap around the floated image. Now imagine how this would look with some actual content in here, rather than just this boring placeholder text that goes on and on, but actually conveys no tangible information at. It simply takes up space and should not really be read.
</p>
<p>
And yet, here you are, still persevering in reading this placeholder text, hoping for some more insights, or some hidden easter egg of content. A joke, perhaps. Unfortunately, there's none of that here.
</p>
</div>