Question

我有带箭头的输入字段（向上，向下）。我旁边有两个按钮+和-。当我单击输入字段然后单击箭头时，系统从下拉列表中获取值。还行吧。但是当我点击第二个时，系统没有从下拉列表中获取值，但是他添加了1个值。问题出在哪儿？

＆＃13;

$(document).ready(function() {
  $("#quantity_wanted").attr({
    "min": parseInt($('#group_psoft :selected').val())
  });
});

＆＃13;

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<select name="group_psoft" id="group_psoft" class="form-control attribute_select no-print">
  <option value="35" selected="selected" title="35">35</option>
  <option value="36" title="36">36</option>
  <option value="37" title="37">37</option>
  <option value="38" title="38">38</option>
  <option value="39" title="39">39</option>
  <option value="40" title="40">40</option>
</select>
<input name="qty" id="quantity_wanted" class="text" value="1" min="35" type="number">

＆＃13;

＆＃13; 产品名称上方的下拉列表：http://prestashop.suszek.info/pl/summer-dresses/printed-summer-dress

Answer 1

您需要向select添加一个事件监听器，以便每次选择下拉列表时都会更新min。

<select name="group_psoft" id="group_psoft" class="form-control attribute_select no-print" onChange='group_psoft_onChange()'>

在javacript中添加代码以更改函数min内的group_psoft_onChange()的值

$(document).ready(function() {
    function group_psoft_onChange(){
      $("#quantity_wanted").attr({
        "min": parseInt($('#group_psoft :selected').val())
      });
    }
});

Answer 2

由于Rohit Agrawal Jquery解决方案效果很好，这是答案的JavaScript版本，因为您标记了JavaScript。

更短的版本

＆＃13;

function dropdownChanged(d){
document.getElementById("quantity_wanted").value = d.value;
}

＆＃13;

<select name="group_psoft" id="group_psoft" class="form-control attribute_select no-print" onchange="dropdownChanged(this)">
  <option value="35" selected="selected" title="35">35</option>
  <option value="36" title="36">36</option>
  <option value="37" title="37">37</option>
  <option value="38" title="38">38</option>
  <option value="39" title="39">39</option>
  <option value="40" title="40">40</option>
</select>
<input name="qty" id="quantity_wanted" class="text" value="1" min="35" type="number">

＆＃13;

其他选项

＆＃13;

var d = document.getElementById("group_psoft");
d.addEventListener("change",dropdownChanged);
function dropdownChanged(){
  var dropdownValue = d.options[d.selectedIndex].value;
  document.getElementById("quantity_wanted").value = dropdownValue;
}

＆＃13;

<select name="group_psoft" id="group_psoft" class="form-control attribute_select no-print">
  <option value="35" selected="selected" title="35">35</option>
  <option value="36" title="36">36</option>
  <option value="37" title="37">37</option>
  <option value="38" title="38">38</option>
  <option value="39" title="39">39</option>
  <option value="40" title="40">40</option>
</select>
<input name="qty" id="quantity_wanted" class="text" value="1" min="35" type="number">

＆＃13;

如何使用jquery在输入字段中更改属性min

2 个答案: