layui下拉联动

layui下写入监听，

searchPname 是第一个下拉框

searchParkingname 是第二个下拉框

            form.on('select(searchPname)', function(data){
                $.getJSON(apiCtxPath + "/comuser/vipuser/userVipByParkingarea?parkingsvrId="+data.value, function(data){
                    var optionstring = "";
                    console.log(data);
                    for (var i = 0; i < data.list.length; i++) {
                        optionstring += "<option value=\"" + data.list[i].columns.u_parkingarea_id + "\" >" + data.list[i].columns.parkingname + "</option>";
                    }
                    
                 /*    $.each(data.data, function(i,item){
                        
                        
                    }); */
                    $("#searchParkingname").html('<option value=""></option>' + optionstring);
                    form.render('select'); //这个很重要
                });
            });

下面是第二个下拉框html部分

                    <div class="form-group">
                          <label class="control-label" for="ordercode">停车场</label>
                                <select id="searchParkingname" name="searchParkingname" lay-filter="searchParkingname" lay-verify="required" lay-search="">
                                  <option value="">直接选择或搜索选择</option>
                                    <option value=""></option>
                                </select>
                    </div>