javascript - 获取下拉菜单的 href 属性 onchange 的值

Question

我有一个下拉列表，用户可以在其中选择不同的净重。例如(200毫升、300毫升等)。

      <?php 
      foreach($todays_offers as $offer)
      {
         $productname= $offer->product_name;
         $price= $offer->price;
         $brand= $offer->brand;
         $netweight= $offer->netweight;
         <div><?php echo $productname ?></div>
         <div><?php echo $price ?></div>
         <div><?php echo $brand ?></div>
       sql queries come here....
      <select name='netweight' id='netweight' onchange='ItemSelected(this)'>
        foreach ($query1->result() as $row) 
        {
            $net = $row->packing; 
            ?>
            <option id="<?php echo $row->id;?>" value="<?php echo $net;?>"><?php 
            echo $net;?>                            
           </option>
      </select> 
 <div class="product-button">
 <a class="add_cart" data-pname="<?php echo $productname ?>"  data-netweight="<?php echo $netweight?>"  data-price="<?php echo $price?>">
 add to cart</a></div>
}?>

我的问题是当用户选择下拉列表时我想设置将购物车按钮的“data-netweight”属性设置为选定的下拉值。我已经为 onchange 事件编写了 javascript 代码，并且正在获取所选值，但我不知道将其设置为 datta-netweight 属性。

JavaScript

function ItemSelected(dropdown)
{

        var product_id = dropdown.options[dropdown.selectedIndex].id;
        var value = dropdown.options[dropdown.selectedIndex].value; 
        var linkitem = $('.product-button').find('a').data('netweight');

}

引用这张图片

Answer 1

从选择中删除 onchange

<?php 
      foreach($todays_offers as $offer)
      {
         $productname= $offer->product_name;
         $price= $offer->price;
         $brand= $offer->brand;
         $netweight= $offer->netweight;
         <div><?php echo $productname ?></div>
         <div><?php echo $price ?></div>
         <div><?php echo $brand ?></div>
       sql queries come here....
      <select name='netweight' id='netweight'>
        foreach ($query1->result() as $row) 
        {
            $net = $row->packing; 
            ?>
            <option id="<?php echo $row->id;?>" value="<?php echo $net;?>"><?php 
            echo $net;?>                            
           </option>
      </select> 
 <div class="product-button">
 <a class="add_cart" data-pname="<?php echo $productname ?>"  data-netweight="<?php echo $netweight?>"  data-price="<?php echo $price?>">
 add to cart</a></div>
}?>

使用 id 获取所选选项

$(document).ready(function(){
     $("#netweight").change(function(){
        var optionsValue = $("#netweight option:selected").val();
        $(this).closest('a').attr('data-netweight',optionsValue);
     });
});