开发后台的是时候用到多选下拉列表,但下拉列表的项要全选才能提交数据,于是再点保存按钮的时候加两个jq全选下拉列表项,不动下拉列表的时候没有问题,,点保存就会全选下拉列表,但如果手动选择了下拉列表中的其中一项,或者删除其中一项,点保存就没法全选下拉列表,不知道是什么问题,求大神帮看一下,下面是部分代码
<form action="?action=save" method="post" id="myform" name="myform" enctype="multipart/form-data">
<select multiple="multiple" name="duotu[]" class="common-select-multiple" id="duotu">
<option value="/uploads/image/20190717/20190717064658_56532.jpg">/uploads/image/20190717/20190717064658_56532.jpg</option>
<option value="/uploads/image/20190717/20190717064658_22694.jpg">/uploads/image/20190717/20190717064658_22694.jpg</option>
<option value="/uploads/image/20190717/20190717064658_35757.jpg">/uploads/image/20190717/20190717064658_35757.jpg</option>
<option value="/uploads/image/20190717/20190717064658_95940.jpg">/uploads/image/20190717/20190717064658_95940.jpg</option>
</select>
<input id="savebutton" class="botton-common" value="保存" type="submit">
</form>
<script type="text/javascript">
$(function() {
//保存时全选
$("#savebutton").click(function(){
$("#duotu option").attr("selected","selected");
});
});
</script>