更改托管bean的呈现属性 [英] change rendered attribute from managed bean

问题描述

我正在尝试使用JSF，情况如下:

Im am experimenting a bit with JSF, the scenario is the following:

我有一个会话范围的托管bean

I have a session scoped managed bean

@ManagedBean(name = "rand")
@SessionScoped

我已经声明了以下内容(除其他事项外):

where i have declared the following (among other things):

private UIOutput uiOutput;(plus getter and setter)

在我的facelets页面中，

In my facelets page i have

<h:outputLabel for="userGuess"  binding="#{rand.uiOutput}" 
value="#{rand.listSize}" rendered="false"/>

页面上有一个按钮，还有我所拥有的按钮的操作方法

there is a button on the page, and on the action method of the button among other things i have

this.uiOutput.setRendered(true);

但是它似乎不起作用，该元素将不会呈现.

But it does not seem to work, the element will not be rendered.

如果以渲染形式启动它并更改属性(将其设置为true或false)，则它将起作用. 我怀疑这与以下事实有关:未渲染的元素未绑定到我在托管bean中拥有的uiOutput对象.在这种情况下如何使它工作?

If a start it as rendered and change the attribute (setting it true or false) it works. I suspect it has something to do with the fact that the element starting as not rendered is not bound to the uiOutput object i have in my managed bean. How can i make it work in this case?

推荐答案

我更改了一件事，现在可以正常工作了，我更改了按下按钮时运行的方法的返回类型，它返回了一个字符串值，导航到同一页面，它现在返回null，并且JSF不会生成新视图，而是呈现相同的视图，并且一切正常.

There is one thing i changed and now it is working, i changed the return type of the method i run when pressing the button, it returned a string value, navigating to the same page, it now returns null and JSF does not generate a new view , instead it renders the same view, and all is working.

我猜因为每次我将渲染值设置为true或false时都会渲染一个新视图，因为每次将组件设置为在新视图上渲染="false"都无关紧要.

I guess since a new view was rendered each time the fact that i set the render value true or false did not matter since each time the component was set to rendered="false" on the new view.

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