Question

我正在尝试检索确实添加到option元素的自定义数据属性，但是它不起作用。

<p>Select a new car from the list.</p>

<select id="mySelect" onchange="myFunction(this.data-price)">
  <option data-price="250" value="Audi">Audi</option>
  <option data-price="130" value="BMW">BMW</option>
  <option data-price="120" value="Mercedes">Mercedes</option>
  <option data-price="400" value="Volvo">Volvo</option>
</select>

<p>When you select a new car, a function is triggered which outputs the value of the selected car.</p>
<p id="demo"></p>

function myFunction(val) {
  document.getElementById("demo").innerHTML = "You selected: " + val;
  console.log(val);
}

问题是当我将函数调用切换到：

onchange="myFunction(this.value)">

它可以正确返回值，但是当我选择数据价格时，它将undefined返回到控制台。

Answer 1

您的代码说的是“获取数据属性”，并从中减去变量“ price”。第二个问题，您选择的属性上时，住在选项中进行选择。您不能将其像价值一样使用。

您应该在所选选项上使用dataset

function myFunction(sel) {
  var opt = sel.options[sel.selectedIndex];
  var price = opt.dataset.price
  document.getElementById("demo").innerHTML = "You selected: " + price;
}

<p>Select a new car from the list.</p>

<select id="mySelect" onchange="myFunction(this)">
  <option data-price="250" value="Audi">Audi</option>
  <option data-price="130" value="BMW">BMW</option>
  <option data-price="120" value="Mercedes">Mercedes</option>
  <option data-price="400" value="Volvo">Volvo</option>
</select>

<p>When you select a new car, a function is triggered which outputs the value of the selected car.</p>
<p id="demo"></p>

Answer 2

只需访问所选选项的data属性（由于您已对其进行标记，因此它是jQuery示例）：

$("#mySelect").change(function() {
  const $this = $(this); // Cache $(this)
  const dataVal = $this.find(':selected').data('price'); // Get data value
  const selectedVal = $this[0].value;
  alert(`${dataVal}, ${selectedVal}`);
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<p>Select a new car from the list.</p>

<select id="mySelect">
  <option data-price="250" value="Audi">Audi</option>
  <option data-price="130" value="BMW">BMW</option>
  <option data-price="120" value="Mercedes">Mercedes</option>
  <option data-price="400" value="Volvo">Volvo</option>
</select>

<p>When you select a new car, a function is triggered which outputs the value of the selected car.</p>
<p id="demo"></p>

获取数据属性onchange事件

2 个答案: