javascript - 如何在html中的按钮中显示下拉选择？

Question

在这里，我在两个不同的按钮中列出了小时和分钟。我可以下拉小时和分钟，但没有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>

还有我用的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，但它会将值更改为所有下拉列表。 这是我得到的截图

Answer 1

it changing value for all – PvDev

您的问题是下拉菜单还是将值设置到正确的部分？也许这会有所帮助。不确定我是否理解你的问题:
查询

$(".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/

我给了你的组元素一个数据属性来确定你点击的是哪种单元。比我选择带有回调的输出元素。 希望它会有所帮助 (如果有关于如何减少我的代码的想法，我会很高兴在这里讨论它:D)