如何从ActionEvent对象获取组件值? [英] How to get component value from ActionEvent object?

问题描述

我在jsf 1.1中使用ajax4jsf，并且我的代码如下:

i am using ajax4jsf with jsf 1.1 and i have code like:

<h:selectOneMenu id="INPUT_PO_DocCategory" binding="#{PrinceOfficeBean.PO_DocCategory}" style="width:200px;">
          <f:selectItem itemLabel="test" itemValue="123"/>
          <f:selectItem itemLabel="test2" itemValue="456"/>
         <a4j:support event="onchange" actionListener="#{PrinceOfficeBean.processDocumentCategoryValueChange}" reRender="INPUT_PO_DocType" />
</h:selectOneMenu> 

此代码是静态的，我可以通过PO_DocCategory绑定对象获取selectOne值 问题是:是否可以通过动作事件对象在actionlistener中获取组件值?

this code is static and i can get selectOne value through PO_DocCategory binded object the question is: is it possible to get the component value in actionlistener through the action event object ?

public void processDocumentCategoryValueChange(ActionEvent e) throws Exception {
   // get component value from ActionEvent 
 }

推荐答案

JSF中的经典方法是使用输入组件的value属性，例如:

Classic way in JSF is to use value attribute of input component, e.g.:

<h:selectOneMenu value="#{bean.value}">
    ...
</h:selectOneMenu>

输入值将存储在bean的value属性中，并且可以由动作侦听器用来对其进行操作.

The input value will be stored in value attribute of the bean, and can be used by action listener to operate on.

仍然可以通过替代"方式在动作侦听器中获取值:

It is still possible to get the value in action listener in 'alternative' way:

((EditableValueHolder) event.getComponent().getParent()).getValue() 

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