easyUI class="easyui-numberbox" 重新加载无法显示的问题

<li class="item">
<label class="item_title">折扣数：</label>
<div><input type="text" id="discount"  name="discount" style="height:22px;" value="" class="easyui-numberbox" precision="2" max="0.99" fix=""/></div>
</li>
<li class="item">
<label class="item_title">金额：</label>
<div><input type="text" id="sum"  name="sum" style="height:22px;" value="" class="easyui-numberbox" precision="2" min="0" fix=""/></div>
</li>




if(priceruleId==''){
$('#priceruleForm').datagrid('unselectAll');
}else{
$.ajax({
'url': basePath+"product/pricerule/show.action?id="+priceruleId,
'type': 'post',
'dataType: 'json',
'success': function(data){

var json =data['rows'][0];
$('#priceruleForm input').each(function(){
$(this).attr('value', json[this.name]);  
});
strategy.select(json.strategy);
state.select(json.state);
type.select(json.type);

$('#discount').numberbox('setValue',json.discount);
$('#sum').numberbox('setValue',json.sum);


$('#endTime').datebox('setValue',json.endTime);
$('#startTime').datebox('setValue',json.startTime);

}
});

}