1.去layui下载多选插件

插件
原文档
2.引用
<link rel="stylesheet" href="/static/layui-formSelects-master/dist/formSelects-v4.css" />
3.js
<!--下拉多选-->
<script type="text/javascript">
//全局定义一次, 加载formSelects
layui.config({
base: '/static/layui-formSelects-master/src/' //此处路径请自行处理, 可以使用绝对路径
}).extend({
formSelects: 'formSelects-v4'
});
//加载模块
layui.use(['jquery', 'formSelects','form'], function(){
var formSelects = layui.formSelects,
form = layui.form;
var id ='';
form.on('select(aihao)', function(data){
id=data.value
$.get("{:url('work/student')}?id="+id,function (b) {
formSelects.data('select1', 'local', {
arr: b.msg
});
})
})
});
</script>
4.html
<div class="layui-form-item">
<label class="layui-form-label">班级选择</label>
<div class="layui-input-block">
<select name="class_id" lay-filter="aihao">
<option value=""></option>
{volist name="aa" id="class"}
<option class="opt" value="{$class.id}">{$class.name}</option>
{/volist}
</select>
</div>
</div>
<div class="layui-form-item">
<label class="layui-form-label">学生</label>
<div class="layui-input-block">
<select name="student_id" xm-select="select1" id="mySelect" lay-filter="student" >
</select>
</div>
</div>
5.php
// 学生选择
public function student($id = ''){
$students = Db::name("cms_student")->where("class_id",$id)->select();
$data = [];
$class = [];
foreach ($students as $item){
$data['value'] = $item['id'];
$data['name'] = $item['name'];
$class[] = $data;
}
return api_json(0,'success',$class);
}