如何在selectOneMenu中对selectItems进行分组

Question

我想使用primefaces 展示中的示例来对selectOneMenu中的selectItems进行分组:

<h:outputText value="Grouping: " />  
    <p:selectOneMenu value="#{formBean.car}">  
        <f:selectItem itemLabel="Select One" itemValue="" />  
        <f:selectItems value="#{formBean.cars}" />  
    </p:selectOneMenu> 

我的问题是,没有实现bean.现在我不知道,如何在getCars()方法中实现selectItems的分组.我找不到任何其他的例子.

Answer 1

展示的源代码#{formBean}可在此处获得.这是相关的摘录:

private List<SelectItem> cars;

public FormBean() {
    SelectItemGroup g1 = new SelectItemGroup("German Cars");
    g1.setSelectItems(new SelectItem[] {new SelectItem("BMW", "BMW"), new SelectItem("Mercedes", "Mercedes"), new SelectItem("Volkswagen", "Volkswagen")});

    SelectItemGroup g2 = new SelectItemGroup("American Cars");
    g2.setSelectItems(new SelectItem[] {new SelectItem("Chrysler", "Chrysler"), new SelectItem("GM", "GM"), new SelectItem("Ford", "Ford")});

    cars = new ArrayList<SelectItem>();
    cars.add(g1);
    cars.add(g2);
}

因此,你缺少的钥匙是SelectItemGroup.

也可以看看:

• 我们的selectOneMenu维基页面 - "带有群组的动态列表"