如何在html中显示下拉选择按钮？

Question

在这里，我用两个不同的按钮列出小时和分钟。 我可以下拉小时和分钟，但不能在按钮中显示选定的值。

        <div class="btn-group btn-group-sm" role="group">
          <button id="startHour" type="button" class="btn btn-secondary" data-toggle="dropdown" href="#">hour</button>

            <div class="dropdown-menu" aria-labelledby="startHour">
              <a class="dropdown-item" href="#">1</a>
              <a class="dropdown-item" href="#">2</a>
              <a class="dropdown-item" href="#">3</a>
              <a class="dropdown-item" href="#">4</a>
              <a class="dropdown-item" href="#">5</a>
              <a class="dropdown-item" href="#">6</a>
              <a class="dropdown-item" href="#">7</a>
              <a class="dropdown-item" href="#">8</a>
              <a class="dropdown-item" href="#">9</a>
              <a class="dropdown-item" href="#">10</a>
              <a class="dropdown-item" href="#">11</a>
              <a class="dropdown-item" href="#">12</a>
            </div>
            <span style="color:white; background-color:#5A6268">:</span>
<div class="btn-group btn-group-sm" role="group">
          <button id="startMinute" type="button" class="btn btn-secondary" 
data-toggle="dropdown" href="#">min</button>
          <div class="dropdown-menu" aria-labelledby="startMinute">
            <a class="dropdown-item" href="#">00</a>
            <a class="dropdown-item" href="#">05</a>
            <a class="dropdown-item" href="#">10</a>
            <a class="dropdown-item" href="#">15</a>
            <a class="dropdown-item" href="#">20</a>
            <a class="dropdown-item" href="#">25</a>
            <a class="dropdown-item" href="#">30</a>
            <a class="dropdown-item" href="#">35</a>
            <a class="dropdown-item" href="#">40</a>
            <a class="dropdown-item" href="#">45</a>
            <a class="dropdown-item" href="#">50</a>
            <a class="dropdown-item" href="#">55</a>
          </div>
          <button type="button" class="btn btn-secondary">am</button>
          <button type="button" class="btn btn-secondary">zone</button>
          <button type="button" class="btn btn-primary">Set</button>

      </div>

和我用过的javascript

  $(".dropdown-menu a").click(function(){
    var selText = $(this).text();
  $(this).parents('.btn-group').find('.btn-secondary').html(selText);
   });

通过使用上面的js代码，我可以在按钮中显示选定的值，但是它将值更改为所有下拉列表。 这是我得到的屏幕截图

Answer 1

您忘记关闭div

 $(".dropdown-menu a").click(function() { var selText = $(this).text(); $(this).parents('.btn-group').find('.btn-secondary').html(selText); }); 

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.0/css/bootstrap.min.css" integrity="sha384-9gVQ4dYFwwWSjIDZnLEWnxCjeSWFphJiwGPXr1jddIhOegiu1FwO5qRGvFXOdJZ4" crossorigin="anonymous"> <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.0/umd/popper.min.js" integrity="sha384-cs/chFZiN24E4KMATLdqdvsezGxaGsi4hLGOzlXwp5UZB1LY//20VyM2taTB4QvJ" crossorigin="anonymous"></script> <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.0/js/bootstrap.min.js" integrity="sha384-uefMccjFJAIv6A+rW+L4AHf99KvxDjWSu1z9VI8SKNVmz4sk7buKt/6v9KI65qnm" crossorigin="anonymous"></script> <div class="btn-group btn-group-sm" role="group"> <button id="startHour" type="button" class="btn btn-secondary" data-toggle="dropdown" href="#">hour</button> <div class="dropdown-menu" aria-labelledby="startHour"> <a class="dropdown-item" href="#">1</a> <a class="dropdown-item" href="#">2</a> <a class="dropdown-item" href="#">3</a> <a class="dropdown-item" href="#">4</a> <a class="dropdown-item" href="#">5</a> <a class="dropdown-item" href="#">6</a> <a class="dropdown-item" href="#">7</a> <a class="dropdown-item" href="#">8</a> <a class="dropdown-item" href="#">9</a> <a class="dropdown-item" href="#">10</a> <a class="dropdown-item" href="#">11</a> <a class="dropdown-item" href="#">12</a> </div> </div> <span style="color:white; background-color:#5A6268">:</span> <div class="btn-group btn-group-sm" role="group"> <button id="startMinute" type="button" class="btn btn-secondary" data-toggle="dropdown" href="#">min</button> <div class="dropdown-menu" aria-labelledby="startMinute"> <a class="dropdown-item" href="#">00</a> <a class="dropdown-item" href="#">05</a> <a class="dropdown-item" href="#">10</a> <a class="dropdown-item" href="#">15</a> <a class="dropdown-item" href="#">20</a> <a class="dropdown-item" href="#">25</a> <a class="dropdown-item" href="#">30</a> <a class="dropdown-item" href="#">35</a> <a class="dropdown-item" href="#">40</a> <a class="dropdown-item" href="#">45</a> <a class="dropdown-item" href="#">50</a> <a class="dropdown-item" href="#">55</a> </div> </div> 

Answer 2

改变所有人的价值– PvDev

您的问题是否在下拉列表中或将值设置为正确的部分？ 也许这会有所帮助。 不知道我是否理解您的问题：
jQuery的

$(".dropdown-menu a").click(function(){
    var selText = $(this).text();
    var currentBtn = $(this).closest(".btn-group").children("button");
    var currentUnit = currentBtn.data("unit");
    currentBtn.html(selText);
        console.log(currentUnit);
    $("."+ currentUnit).text(selText);
   });

HTML

<div class="btn-group btn-group-sm" role="group">
  <button id="startHour" type="button" data-unit="hours"  class="btn btn-secondary" data-toggle="dropdown" href="#">hour</button>
  <div class="dropdown-menu" aria-labelledby="startHour">
    <a class="dropdown-item" href="#">1</a>
    <a class="dropdown-item" href="#">2</a>
    <a class="dropdown-item" href="#">3</a>
    <a class="dropdown-item" href="#">4</a>
    <a class="dropdown-item" href="#">5</a>
    <a class="dropdown-item" href="#">6</a>
    <a class="dropdown-item" href="#">7</a>
    <a class="dropdown-item" href="#">8</a>
    <a class="dropdown-item" href="#">9</a>
    <a class="dropdown-item" href="#">10</a>
    <a class="dropdown-item" href="#">11</a>
    <a class="dropdown-item" href="#">12</a>
  </div>
  <span style="color:white; background-color:#5A6268">:</span>
</div>
<div class="btn-group btn-group-sm" role="group">
  <button id="startMinute" type="button" data-unit="minutes" class="btn btn-secondary" data-toggle="dropdown" href="#">min</button>
  <div class="dropdown-menu" aria-labelledby="startMinute">
    <a class="dropdown-item" href="#">00</a>
    <a class="dropdown-item" href="#">05</a>
    <a class="dropdown-item" href="#">10</a>
    <a class="dropdown-item" href="#">15</a>
    <a class="dropdown-item" href="#">20</a>
    <a class="dropdown-item" href="#">25</a>
    <a class="dropdown-item" href="#">30</a>
    <a class="dropdown-item" href="#">35</a>
    <a class="dropdown-item" href="#">40</a>
    <a class="dropdown-item" href="#">45</a>
    <a class="dropdown-item" href="#">50</a>
    <a class="dropdown-item" href="#">55</a>
  </div>
</div>
<div class="output">
  <button type="button" class="hours btn btn-secondary">am</button>
  <button type="button" class="minutes btn btn-secondary">zone</button>
  <button type="button" class="seconds btn btn-primary">Set</button>
</div>

https://jsfiddle.net/Rakowu/t982sLuj/1/

我给您的组元素一个数据属性，以确定您单击的单位是什么。 比我选择带有回调的输出元素。 希望对您有所帮助（如果对减少代码量有想法，我很乐意在此进行：D）