一个简单的下拉列表

实现功能：列出所有的部门，并根据选择的部门名称列出该部门下的所有员工。
1.页面主要代码： 
<af:table value="#{bindings.EmployeesView1.collectionModel}"
                        var="row" rows="#{bindings.EmployeesView1.rangeSize}"
                        emptyText="#{bindings.EmployeesView1.viewable ? 'No data to display.' : 'Access Denied.'}"
                        fetchSize="#{bindings.EmployeesView1.rangeSize}"
                        rowBandingInterval="0"
                        filterModel="#{bindings.EmployeesView1Query.queryDescriptor}"
                        queryListener="#{bindings.EmployeesView1Query.processQuery}"
                        filterVisible="true"
   varStatus="vs"  （主要使用这个）
                        selectedRowKeys="#{bindings.EmployeesView1.collectionModel.selectedRow}"
                        selectionListener="#{bindings.EmployeesView1.collectionModel.makeCurrent}"
                        rowSelection="single" id="t1">
在目标字段里加上facet：
<af:column sortProperty="DepartmentId" filterable="true"
                           sortable="true"
                           headerText="#{bindings.EmployeesView1.hints.DepartmentId.label}"
                           id="c11">
                  <af:outputText value="#{row.DepartmentId}" id="ot4">
                    <af:convertNumber groupingUsed="false"
                                      pattern="#{bindings.EmployeesView1.hints.DepartmentId.format}"/>
                  </af:outputText>
  ----------从下面开始---------
                  <f:facet name="filter">
                    <af:selectOneChoice value="#{vs.filterCriteria.DepartmentId}"
                                        label="Label 1" id="soc1">
                      <af:forEach items="#{bindings.DepartmentsView1.rangeSet}"
                                  var="rowlist">
                        <f:selectItem itemLabel="#{rowlist.DepartmentName}"
                                      itemValue="#{rowlist.DepartmentId}"/>
                      </af:forEach>
                    </af:selectOneChoice>
                  </f:facet>
  ----------到上面结束---------
</af:column>
2.加上绑定。
（1）Tab页从Source切换到Bindings,点击绿色加号，在弹出窗体Insert Item里选择tree，点中OK.
（2）在窗体Create Tree Binding中，做一下设置：
 a.Root Data Source：你可以从下拉列表中选择或者点击Add按钮添加。
 b.Tree Level Rules：点击绿色加号按钮添加规则。
 c.Available Attributes：将需要使用的属性从左边弄到右边。点击OK
3.保存and运行页面。