答案 0 :(得分:-1)
更新后,将元素设置为:focus。您可以通过CSS更改焦点状态的样式:
.select:focus {
outline: 2px solid green;
}
<select class="select" name="" id="">
<option value="1">1</option>
<option value="1">2</option>
<option value="1">3</option>
</select>
<select name="" id="">
<option value="1">1</option>
<option value="1">2</option>
<option value="1">3</option>
</select>