Layui动态生成select下拉选择框不显示的解决办法

layui.use('form', function(){ //此段代码必不可少
 var form = layui.form;
 form.render();
});

<div class="layui-form-item">
 <label class="layui-form-label">执行周期</label>
 <div class="layui-input-inline" style="width: 90px;">
  <select name="period_type" lay-verify="required" lay-filter="period">
   <option value="week">每星期</option>
   <option value="day">每天</option>
   <option value="day-n">N天</option>
   <option value="hour">每小时</option>
   <option value="hour-n">N小时</option>
   <option value="minute-n">N分钟</option>
   <option value="month">每月</option>
  </select>
 </div>
 <div id="suboption">
  <!-- 默认每星期 -->
  <div>
  <div class="layui-input-inline" style="width: 90px;">
   <select name="week">
    <option value="1">周一</option>
    <option value="2">周二</option>
    <option value="3">周三</option>
    <option value="4">周四</option>
    <option value="5">周五</option>
    <option value="6">周六</option>
    <option value="0">周日</option>
   </select>
  </div>
  <div class="layui-input-inline" style="width: 60px;">
   <input type="number" name="hour" value="1" max="23" maxlength="2" min="0" class="layui-input"/>
  </div>
  <div class="layui-input-inline" style="width: 50px; vertical-align: middle; margin-left: -11px;">
   <input type="text" class="layui-input" readonly value="小时" style=" background-color: #f6f6f6;">
  </div>
  <div class="layui-input-inline" style="width: 60px;">
   <input type="number" name="minute" value="30" maxlength="2" max="59" min="0" class="layui-input"/>
  </div>
  <div class="layui-input-inline" style="width: 50px; vertical-align: middle; margin-left: -11px;">
   <input type="text" class="layui-input" readonly value="分钟" style=" background-color: #f6f6f6;">
  </div>
 </div>
 </div>

</div>

layui.use('form', function(){
 var form = layui.form;
 form.on('select(period)', function(data){
  var num = data.elem.selectedIndex; //获取对应option的索引排序
  num = num + 1;
  $('#suboption').empty();
  switch (num)
  {
   case 1: //每星期
    $("#suboption").append(`<div>
  <div class="layui-input-inline" style="width: 90px; height: 36px; font-size: 14px;" id="weekid" >
   <select name="week" style="height: 36px;">
    <option value="1">周一</option>
    <option value="2">周二</option>
    <option value="3">周三</option>
    <option value="4">周四</option>
    <option value="5">周五</option>
    <option value="6">周六</option>
    <option value="0">周日</option>
   </select>
  </div>
  <div class="layui-input-inline" style="width: 60px;">
   <input type="number" name="hour" value="1" max="23" maxlength="2" min="0" class="layui-input"/>
  </div>
  <div class="layui-input-inline" style="width: 50px; vertical-align: middle; margin-left: -11px;">
   <input type="text" class="layui-input" readonly value="小时" style=" background-color: #f6f6f6;">
  </div>
  <div class="layui-input-inline" style="width: 60px;">
   <input type="number" name="minute" value="30" maxlength="2" max="59" min="0" class="layui-input"/>
  </div>
  <div class="layui-input-inline" style="width: 50px; vertical-align: middle; margin-left: -11px;">
   <input type="text" class="layui-input" readonly value="分钟" style=" background-color: #f6f6f6;">
  </div>
 </div>`);
    layui.use('form', function(){ //此段代码必不可少
     var form = layui.form;
     form.render();
    });
    break;
   case 2: //每天
    $("#suboption").append(` <div>
   <div class="layui-input-inline" style="width: 60px;">
    <input type="number" name="hour" value="1" max="23" maxlength="2" min="0" class="layui-input"/>
   </div>
   <div class="layui-input-inline" style="width: 50px; vertical-align: middle; margin-left: -11px;">
    <input type="text" class="layui-input" readonly value="小时" style=" background-color: #f6f6f6;">
   </div>
   <div class="layui-input-inline" style="width: 60px;">
    <input type="number" name="minute" value="30" maxlength="2" max="59" min="0" class="layui-input"/>
   </div>
   <div class="layui-input-inline" style="width: 50px; vertical-align: middle; margin-left: -11px;">
    <input type="text" class="layui-input" readonly value="分钟" style=" background-color: #f6f6f6;">
   </div>
  </div>`);
    break;
   case 3: //N天
    $("#suboption").append(` <div>
   <div class="layui-input-inline" style="width: 60px;">
    <input type="number" name="where1" value="3" max="31" maxlength="2" min="0" class="layui-input"/>
   </div>
   <div class="layui-input-inline" style="width: 50px; vertical-align: middle; margin-left: -11px;">
    <input type="text" class="layui-input" readonly value="天" style=" background-color: #f6f6f6;">
   </div>
   <div class="layui-input-inline" style="width: 60px;">
    <input type="number" name="hour" value="1" max="23" maxlength="2" min="0" class="layui-input"/>
   </div>
   <div class="layui-input-inline" style="width: 50px; vertical-align: middle; margin-left: -11px;">
    <input type="text" class="layui-input" readonly value="小时" style=" background-color: #f6f6f6;">
   </div>
   <div class="layui-input-inline" style="width: 60px;">
    <input type="number" name="minute" value="30" maxlength="2" max="59" min="0" class="layui-input"/>
   </div>
   <div class="layui-input-inline" style="width: 50px; vertical-align: middle; margin-left: -11px;">
    <input type="text" class="layui-input" readonly value="分钟" style=" background-color: #f6f6f6;">
   </div>
  </div>`);
    break;
   case 4: //每小时
    $("#suboption").append(`<div>
   <div class="layui-input-inline" style="width: 60px;">
    <input type="number" name="minute" value="30" maxlength="2" max="59" min="0" class="layui-input"/>
   </div>
   <div class="layui-input-inline" style="width: 50px; vertical-align: middle; margin-left: -11px;">
    <input type="text" class="layui-input" readonly value="分钟" style=" background-color: #f6f6f6;">
   </div>
  </div>`);
    break;
   case 5: //N小时
    $("#suboption").append(` <div>
   <div class="layui-input-inline" style="width: 60px;">
    <input type="number" name="hour" value="1" max="23" maxlength="2" min="0" class="layui-input"/>
   </div>
   <div class="layui-input-inline" style="width: 50px; vertical-align: middle; margin-left: -11px;">
    <input type="text" class="layui-input" readonly value="小时" style=" background-color: #f6f6f6;">
   </div>
   <div class="layui-input-inline" style="width: 60px;">
    <input type="number" name="minute" value="30" maxlength="2" max="59" min="0" class="layui-input"/>
   </div>
   <div class="layui-input-inline" style="width: 50px; vertical-align: middle; margin-left: -11px;">
    <input type="text" class="layui-input" readonly value="分钟" style=" background-color: #f6f6f6;">
   </div>
  </div>`);
    break;
   case 6: //N分钟
    $("#suboption").append(`<div>
   <div class="layui-input-inline" style="width: 60px;">
    <input type="number" name="minute" value="3" maxlength="2" max="59" min="0" class="layui-input"/>
   </div>
   <div class="layui-input-inline" style="width: 50px; vertical-align: middle; margin-left: -11px;">
    <input type="text" class="layui-input" readonly value="分钟" style=" background-color: #f6f6f6;">
   </div>
  </div>`);
    break;
   case 7: //每月
    $("#suboption").append(` <div>
   <div class="layui-input-inline" style="width: 60px;">
    <input type="number" name="where1" value="3" max="31" maxlength="2" min="0" class="layui-input"/>
   </div>
   <div class="layui-input-inline" style="width: 50px; vertical-align: middle; margin-left: -11px;">
    <input type="text" class="layui-input" readonly value="日" style=" background-color: #f6f6f6;">
   </div>
   <div class="layui-input-inline" style="width: 60px;">
    <input type="number" name="hour" value="1" max="23" maxlength="2" min="0" class="layui-input"/>
   </div>
   <div class="layui-input-inline" style="width: 50px; vertical-align: middle; margin-left: -11px;">
    <input type="text" class="layui-input" readonly value="小时" style=" background-color: #f6f6f6;">
   </div>
   <div class="layui-input-inline" style="width: 60px;">
    <input type="number" name="minute" value="30" maxlength="2" max="59" min="0" class="layui-input"/>
   </div>
   <div class="layui-input-inline" style="width: 50px; vertical-align: middle; margin-left: -11px;">
    <input type="text" class="layui-input" readonly value="分钟" style=" background-color: #f6f6f6;">
   </div>
  </div>`);
    break;
  }
 });

});