Action code can't be null or empty string

报错原因是因为 在xml配置按钮的时候 没有给code属性

<!-- 订单列表 插入下载WMS按钮-->
    <bean class="nc.ui.pubapp.plugin.action.InsertActionInfo">
        <property name="actionContainer" ref="actionsOfList" />
        <property name="actionType" value="notedit" />
        <property name="target" ref="printActionGroup" />
        <property name="pos" value="after" />
        <property name="action" ref="DeliveryAction" />
    </bean>


    <!-- 自定义 按钮 -->
    <bean id="DeliveryAction" class="nc.ui.sf.delivery.action.DeliveryAction">      
        <property name="model" ref="ManageAppModel" />
        <property name="editor" ref="billFormEditor" />
        <property name="code" value="delivery_wms" />   
    </bean>