twitter-bootstrap - 带有下拉菜单的 Bootstrap-4 按钮选择的值不显示

Question

我使用的是 bootstrap-4 带下拉菜单的按钮 我有一些问题选择的值不显示此下拉菜单？我想知道正确选择值时如何设置货币名称，我的代码有问题，为此获取一次所有值，您可以理解该问题，请查看snippet

$(".dropdown-menu ").click(function(){

  $(this).parents(".input-group-btn").find('.btn').text($(this).text());
 

});

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.2/css/bootstrap.min.css" integrity="sha384-PsH8R72JQ3SOdhVi3uxftmaW6Vc51MKb0q5P2rRUpPvrszuE4W1povHYgTpBfshb" 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/1.12.3/umd/popper.min.js" integrity="sha384-vFJXuSJphROIrBnz7yo7oB41mKfc8JzQZiCq4NCceLEaO4IHwicKwpJf9c9IpFgh" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.2/js/bootstrap.min.js" integrity="sha384-alpBpkh1PFOepccYVYDB4do5UnbKysX5WZXm3XxPqe5iKTfUKjNkCk9SaVuEZflJ" crossorigin="anonymous"></script>
<div class="row">
  <div class="col-lg-6">
    <div class="input-group">
      <div class="input-group-btn">
        <button type="button" class="btn btn-secondary dropdown-toggle" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
         Currency
        </button>
        <div class="dropdown-menu">
          <a class="dropdown-item" href="#">USD</a>
          <a class="dropdown-item" href="#">AUS</a>
       
        </div>
      </div>
      <input type="text" class="form-control" aria-label="Text input with dropdown button">
    </div>
  </div>
 
</div>

Answer 1

我解决了我的问题 解决方案01
按钮像选择框一样工作，我更改了我的 script

<script>

            $('.dropdown-menu a').on('click', function(){    
        $('.dropdown-toggle').html($(this).html());    
    })
        </script>

现在它为我工作

	$('.dropdown-menu a').on('click', function(){    
    $('.dropdown-toggle').html($(this).html());    
})

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.2/css/bootstrap.min.css" integrity="sha384-PsH8R72JQ3SOdhVi3uxftmaW6Vc51MKb0q5P2rRUpPvrszuE4W1povHYgTpBfshb" 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/1.12.3/umd/popper.min.js" integrity="sha384-vFJXuSJphROIrBnz7yo7oB41mKfc8JzQZiCq4NCceLEaO4IHwicKwpJf9c9IpFgh" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.2/js/bootstrap.min.js" integrity="sha384-alpBpkh1PFOepccYVYDB4do5UnbKysX5WZXm3XxPqe5iKTfUKjNkCk9SaVuEZflJ" crossorigin="anonymous"></script>
<div class="row">
  <div class="col-lg-6">
    <div class="input-group">
      <div class="input-group-btn">
        <button type="button" class="btn btn-secondary dropdown-toggle" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
         Currency
        </button>
        <div class="dropdown-menu">
          <a class="dropdown-item" href="#">USD</a>
          <a class="dropdown-item" href="#">AUS</a>
       
        </div>
      </div>
      <input type="text" class="form-control" aria-label="Text input with dropdown button">
    </div>
  </div>
 
</div>

解决方案-02 脚本

        $(".dropdown-menu a ").click(function(){

  $(this).parents(".input-group-btn").find('.btn').text($(this).text());


});

$(".dropdown-menu a ").click(function(){

  $(this).parents(".input-group-btn").find('.btn').text($(this).text());
 

});

   <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.2/css/bootstrap.min.css" integrity="sha384-PsH8R72JQ3SOdhVi3uxftmaW6Vc51MKb0q5P2rRUpPvrszuE4W1povHYgTpBfshb" 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/1.12.3/umd/popper.min.js" integrity="sha384-vFJXuSJphROIrBnz7yo7oB41mKfc8JzQZiCq4NCceLEaO4IHwicKwpJf9c9IpFgh" crossorigin="anonymous"></script>
    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.2/js/bootstrap.min.js" integrity="sha384-alpBpkh1PFOepccYVYDB4do5UnbKysX5WZXm3XxPqe5iKTfUKjNkCk9SaVuEZflJ" crossorigin="anonymous"></script>
    <div class="row">
      <div class="col-lg-6">
        <div class="input-group">
          <div class="input-group-btn">
            <button type="button" class="btn btn-secondary dropdown-toggle" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
             Currency
            </button>
            <div class="dropdown-menu">
              <a class="dropdown-item" href="#">USD</a>
              <a class="dropdown-item" href="#">AUS</a>
           
            </div>
          </div>
          <input type="text" class="form-control" aria-label="Text input with dropdown button">
        </div>
      </div>
     
    </div>