在Bootstrap 4中左右对齐模态页脚按钮

Question

Bootstrap 4使用flex-box作为模态页脚。如果我想要两个按钮，一个在左边，一个在右边，我该如何让它正常工作？

下面的代码试图使用div.row与col-sm-6但不起作用。

<script src="https://code.jquery.com/jquery-3.1.1.slim.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/tether/1.4.0/js/tether.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/js/bootstrap.min.js"></script>
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/css/bootstrap.min.css" rel="stylesheet"/>

<!-- Button trigger modal -->
<button type="button" class="btn btn-primary" data-toggle="modal" data-target="#myModal">
  Launch demo modal
</button>

<!-- Modal -->
<div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="exampleModalLabel" aria-hidden="true">
  <div class="modal-dialog" role="document">
    <div class="modal-content">
      <div class="modal-header">
        <h5 class="modal-title" id="exampleModalLabel">Modal title</h5>
        <button type="button" class="close" data-dismiss="modal" aria-label="Close">
          <span aria-hidden="true">&times;</span>
        </button>
      </div>
      <div class="modal-body">
        ...
      </div>
      <div class="modal-footer">
      <div class="row">
        <div class="col-sm-6 text-left">
        <button type="button" class="btn btn-primary">Save changes</button>
        </div>
        <div class="col-sm-6 text-right">
        <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
        </div>
      </div>
      </div>
    </div>
  </div>
</div>

Answer 1

既然modal-footer在Bootstrap 4中是“display：flex”，那么使用自动边距是最简单的。在左侧按钮上使用mr-auto。

<div class="modal-footer">
     <button type="button" class="btn btn-primary mr-auto">Save changes</button>
     <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
</div>

Demo

另见：Left align and right align within div in Bootstrap

Answer 2

modal-footer是display:flex;。因此，对齐其元素（例如按钮）的更好方法是使用弹性规则。 Bootstrap 4提供了新的实用程序类来修改这些flex规则（例如.justify-content-[modifier]）。所以我认为更好的选择应该如下：

<div class="modal-footer justify-content-between">
  <button type="button" class="btn btn-primary">Save changes</button>
  <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
</div>

<script src="https://code.jquery.com/jquery-3.1.1.slim.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/tether/1.4.0/js/tether.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/js/bootstrap.min.js"></script>
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/css/bootstrap.min.css" rel="stylesheet"/>

<!-- Button trigger modal -->
<button type="button" class="btn btn-primary" data-toggle="modal" data-target="#myModal">
  Launch demo modal
</button>

<!-- Modal -->
<div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="exampleModalLabel" aria-hidden="true">
  <div class="modal-dialog" role="document">
    <div class="modal-content">
      <div class="modal-header">
        <h5 class="modal-title" id="exampleModalLabel">Modal title</h5>
        <button type="button" class="close" data-dismiss="modal" aria-label="Close">
          <span aria-hidden="true">&times;</span>
        </button>
      </div>
      <div class="modal-body">
        ...
      </div>
      <div class="modal-footer justify-content-between">
        <button type="button" class="btn btn-primary">Save changes</button>
        <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
      </div>
    </div>
  </div>
</div>

Answer 3

在IE中使用的唯一方法是使用w-100。 mx-auto和mr和ml-auto都似乎从包含元素溢出了按钮。

<div class="modal-footer">
  <div class="w-100">
    <button type="button" class="btn btn-default">Cancel</button>
    <button type="button" class="btn btn-primary float-right">Save</button>
  </div>
</div>

Answer 4

对于Bootstrap 4

我们使用Spacing，Bootstrap包含各种缩写和填充响应边距实用程序类来修改元素的外观。对于xs和{property} {sides} - {breakpoint} - {size}，对于sm，md，lg和xl，使用格式{property} {sides} - {size}来命名类。

更多信息：https://getbootstrap.com/docs/4.1/utilities/spacing/

<!--Footer-->
<div class="modal-footer">
  <button type="submit" class="btn btn-primary ml-auto">Enviar</button>
  <button type="button" class="btn btn-danger mr-auto" data-dismiss="modal">Cerrar</button>
</div>

Answer 5

这很简单，对我很有帮助

 <div class="modal-footer">
 <button id="pagePrintBtn" type="button" class="btn btn-primary" style= "float: left;">Print</button>
 </div>

Answer 6

  <div class="modal-footer justify-content-start">
                    <input type="hidden" value="" name="">
                    <button id="pagePrintBtn" type="button" class="btn btn-primary">Print</button>
                    <button type="button" class="btn btn-secondary ml-auto" data-dismiss="modal">Delete</button>
                    <button type="button" class="btn btn-primary" id=asd>Save</button>
                </div>

Answer 7

对于IE，您可以使用.justify-content-between帮助程序类形式bootstrap作为父元素。在这种情况下为.modal-footer。

例如：

<div class="modal-footer justify-content-between">
     <button type="button" class="btn btn-primary">Save changes</button>
     <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
</div>

Answer 8

对于任何想要3个按钮的人，例如右边的2个和左边的1个：

<div class="modal-footer justify-content-between">                    
   <button type="submit" class="btn btn-danger">Delete</button>                                    
   <div>
       <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
       <button type="submit" class="btn btn-primary">Save changes</button>
   </div>  
</div>