primefaces更新屬性不起作用

Question

每當我在Home.xhtml頁面上運行下面的代碼，我會得到以下異常。我嘗試使用id = items調用面板的內容，但沒有成功。它表示編譯器無法找到具有items標識符的組件。

1）Home.xhtml

的一部分

<h:form> 
    <p:commandButton type="submit" value="Speak Out" action="#{statusBean.save}" ajax="true" styleClass="buttonstyle" update="items"/>       
</h:form> 


<p:panel id="items">  
    //content  
</p:panel> 

2）異常

Mar 12, 2013 1:38:04 AM com.sun.faces.application.view.FaceletViewHandlingStrategy handleRenderException 
SEVERE: Error Rendering View[/Home.xhtml] 
javax.faces.FacesException: Cannot find component with identifier "items" in view. 
    at org.primefaces.util.ComponentUtils.findClientIds(ComponentUtils.java:249) 
    at org.primefaces.renderkit.CoreRenderer.buildAjaxRequest(CoreRenderer.java:222) 
    at org.primefaces.component.commandbutton.CommandButtonRenderer.encodeMarkup(CommandButtonRenderer.java:81) 
    at org.primefaces.component.commandbutton.CommandButtonRenderer.encodeEnd(CommandButtonRenderer.java:53) 
    at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:879) 
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1650) 
    at javax.faces.render.Renderer.encodeChildren(Renderer.java:164) 
    at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:849) 
    at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeRecursive(HtmlBasicRenderer.java:300) 
    at com.sun.faces.renderkit.html_basic.GridRenderer.renderRow(GridRenderer.java:181) 
    at com.sun.faces.renderkit.html_basic.GridRenderer.encodeChildren(GridRenderer.java:125) 
    at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:849) 
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1643) 
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1646) 
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1646) 
    at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:389) 
    at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:127) 
    at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:117) 
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:97) 
    at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:135) 
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:309) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) 
    at org.primefaces.webapp.filter.FileUploadFilter.doFilter(FileUploadFilter.java:79) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) 
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:225) 
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123) 
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472) 
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168) 
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98) 
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927) 
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118) 
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407) 
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1001) 
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579) 
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310) 
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110) 
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) 
    at java.lang.Thread.run(Thread.java:722) 

Mar 12, 2013 1:38:04 AM org.apache.catalina.core.StandardWrapperValve invoke 
SEVERE: Servlet.service() for servlet [Faces Servlet] in context with path [/FreeBird_v.6] threw exception [Cannot find component with identifier "items" in view.] with root cause 
javax.faces.FacesException: Cannot find component with identifier "items" in view. 
    at org.primefaces.util.ComponentUtils.findClientIds(ComponentUtils.java:249) 
    at org.primefaces.renderkit.CoreRenderer.buildAjaxRequest(CoreRenderer.java:222) 
    at org.primefaces.component.commandbutton.CommandButtonRenderer.encodeMarkup(CommandButtonRenderer.java:81) 
    at org.primefaces.component.commandbutton.CommandButtonRenderer.encodeEnd(CommandButtonRenderer.java:53) 
    at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:879) 
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1650) 
    at javax.faces.render.Renderer.encodeChildren(Renderer.java:164) 
    at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:849) 
    at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeRecursive(HtmlBasicRenderer.java:300) 
    at com.sun.faces.renderkit.html_basic.GridRenderer.renderRow(GridRenderer.java:181) 
    at com.sun.faces.renderkit.html_basic.GridRenderer.encodeChildren(GridRenderer.java:125) 
    at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:849) 
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1643) 
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1646) 
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1646) 
    at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:389) 
    at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:127) 
    at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:117) 
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:97) 
    at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:135) 
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:309) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) 
    at org.primefaces.webapp.filter.FileUploadFilter.doFilter(FileUploadFilter.java:79) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) 
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:225) 
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123) 
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472) 
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168) 
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98) 
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927) 
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118) 
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407) 
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1001) 
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579) 
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310) 
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110) 
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) 
    at java.lang.Thread.run(Thread.java:722) 

Answer 1

歐凱，不久你應該嘗試:items，因爲它的組件樹之外。有關使用primefaces的ajax行爲的更多詳細信息，您可以從here中查看展示中的示例。此外，在這種情況下，您可以使用firebug來觀察組件。 編輯： 經過BalusC的警告，你的問題在於不是因爲它不在同一個組件樹內是正確的，因爲它不在同一個NamingContainer中。

標準組件如h: form，f: subview和h: dataTable是命名容器。大多數組件都有一些命名容器，所以在你的情況下，它在標籤之外，因此:items將是正確的方式來引用它。

請參閱這些崗位幫助你理解題目很好：

• Jsf How to create a Naming Container
• Naming Container and Jsf