PrimeFaces - JSF树的上下文菜单无法显示

Question

现在我想使用JSF树的鼠标右键菜单，就像链接的例子一样。当我单击鼠标右键时，菜单可以立即显示和消失。我不知道如何显示鼠标右键菜单（treecontext）。你能就此提出一些建议吗？感谢。

http://www.primefaces.org/showcase/ui/treeContextMenu.jsf

<ui:composition xmlns="http://www.w3.org/1999/xhtml"       
      xmlns:h="http://java.sun.com/jsf/html"       
      xmlns:f="http://java.sun.com/jsf/core"       
      xmlns:ui="http://java.sun.com/jsf/facelets"       
      xmlns:p="http://primefaces.org/ui">

    <h:form id="treeform">  


    <p:tree value="#{treeBean.root}" var="node" id="tree" rendered="true"  dynamic="true" cache="false" selectionMode="single" selection="#{treeBean.selectedNode}">       
        <p:ajax event="expand"    listener="#{treeBean.onNodeExpand}"/>  
        <p:ajax event="collapse"  listener="#{treeBean.onNodeCollapse}" />
        <p:ajax event="select"    listener="#{tableBean.showScenario}"  update=":mainForm:scenarioDetailTable :mainForm:dynaFormGroup :mainForm:breadcrumbmenu :mainForm:accordingpanel1:treeform:tree :mainForm:accordingpanel1:treeform:treecontext" />         
        <p:ajax event="unselect"  listener="#{treeBean.onNodeUnselect}" update=":mainForm:scenarioDetailTable :mainForm:dynaFormGroup :mainForm:breadcrumbmenu :mainForm:accordingpanel1:treeform:tree :mainForm:accordingpanel1:treeform:treecontext" /> 
        <p:treeNode id="treeNode" rendered="true" animate="true"  expandedIcon="ui-icon-folder-open" collapsedIcon="ui-icon-folder-collapsed">  
            <h:outputText value="#{node.name}" id="lblNode"/>  
        </p:treeNode>  
    </p:tree>    

    <p:contextMenu id="treecontext" for="tree" rendered="true"  >          
        <p:menuitem value="Add Product"    disabled="#{tableBean.selectedProjectNodeLevel==1?false:true}" icon="ui-icon-contact" action="#{treeBean.setDialogTitle}" update=":mainForm:scenarioDetailTable  :mainForm:accordingpanel1:treeform:tree " oncomplete="PF('createproductdlg').show()"    onclick="PF('createproductdlg').show()" />
        <p:menuitem value="Add Capability" disabled="#{tableBean.selectedProjectNodeLevel==2?false:true}" icon="ui-icon-contact" action="#{treeBean.setDialogTitle}" update=":mainForm:scenarioDetailTable  :mainForm:accordingpanel1:treeform:tree " oncomplete="PF('createcapabilitydlg').show()"    onclick="PF('createcapabilitydlg').show()" />  
        <p:menuitem value="Add Feature"    disabled="#{tableBean.selectedProjectNodeLevel>=3?false:true}" icon="ui-icon-contact" action="#{treeBean.setDialogTitle}" update=":mainForm:scenarioDetailTable  :mainForm:accordingpanel1:treeform:tree " oncomplete="PF('createfeaturedlg').show()"    onclick="PF('createfeaturedlg').show()" />  
        <p:menuitem value="Add Scenario"   disabled="#{tableBean.selectedProjectNodeLevel>=3?false:true}" icon="ui-icon-contact" update=":mainForm:scenarioDetailTable  :mainForm:accordingpanel1:treeform:tree " oncomplete="PF('scenariodlg').show()"  onclick="PF('scenariodlg').show()" /> 
        <p:menuitem value="Delete" update="tree" actionListener="#{treeBean.create}" icon="ui-icon-close"/>  
    </p:contextMenu>
   </h:form>
</ui:composition>

主页代码的某些部分

<h:form id="mainForm">

<p:layout id="fulllayout" fullPage="true">  
<!-- top menu start -->
<p:layoutUnit id="layoutunittop" position="north" size="50">
    <p:breadCrumb id="breadcrumbmenu" rendered="true">  
     <p:menuitem value="Categories" url="#"  />  
     <p:menuitem value="Project" url="#" disabled="true" />   
     <p:menuitem value="Add Product"    disabled="#{tableBean.selectedProjectNodeLevel==1?false:true}" action="#{treeBean.setDialogTitle}" update=":mainForm:scenarioDetailTable  :mainForm:accordingpanel1:treeform:tree " oncomplete="PF('createproductdlg').show()"    onclick="PF('createproductdlg').show()" />
     <p:menuitem value="Add Capability" disabled="#{tableBean.selectedProjectNodeLevel==2?false:true}" action="#{treeBean.setDialogTitle}" update=":mainForm:scenarioDetailTable  :mainForm:accordingpanel1:treeform:tree " oncomplete="PF('createcapabilitydlg').show()"    onclick="PF('createcapabilitydlg').show()" />  
     <p:menuitem value="Add Feature"    disabled="#{tableBean.selectedProjectNodeLevel>=3?false:true}" action="#{treeBean.setDialogTitle}" update=":mainForm:scenarioDetailTable  :mainForm:accordingpanel1:treeform:tree " oncomplete="PF('createfeaturedlg').show()"    onclick="PF('createfeaturedlg').show()" />  
     <p:menuitem value="Add Scenario"   disabled="#{tableBean.selectedProjectNodeLevel>=3?false:true}" update=":mainForm:scenarioDetailTable  :mainForm:accordingpanel1:treeform:tree " oncomplete="PF('scenariodlg').show()"  onclick="PF('scenariodlg').show()" /> 
    </p:breadCrumb>
</p:layoutUnit>
<!-- top menu end -->

 <!-- menu begin -->
 <p:layoutUnit id="layoutunitleft" position="west" size="360"  resizable="true" collapsible="true" header="Options" minSize="260">
    <p:accordionPanel id="accordingpanel1" rendered="true" >                         
     <p:tab id="accordingpanel1tab" title="Project">      
       <ui:include src="tree.xhtml" /> 
     </p:tab>                          
     <p:tab title="Test Set">                             
       <h:outputText value="Test Set" />                         
     </p:tab>                          
     <p:tab title="Report">                             
      <!--   <h:outputText value="Report" />  -->
      <!--   <p:calendar mode="inline" navigator="none"/> -->                        
     </p:tab>                     
     </p:accordionPanel>                 
  </p:layoutUnit>
  <!-- menu end -->
....