在本章中，我们将了解RichFaces Technology提供的不同选择组件.
使用此标签，我们可以从填充的列表中选择一个值.它还允许我们向另一个List添加和删除列表组件.以下示例演示了它的工作原理.继续创建一个xhtml文件并将其命名为"pickListExample.xhtml"并将以下代码放入其中.
<?xml version = "1.0" encoding = "UTF-8"?>
<!DOCTYPE html>
<html 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:a4j = "http://richfaces.org/a4j"
xmlns:rich = "http://richfaces.org/rich">
<h:head>
<title>PickList Example</title>
</h:head>
<h:body>
<h:form>
<h:outputText value = "Pick List Example"/>
<br/>
<br/>
<rich:pickList value = "#{managedBean.subjectList}"
sourceCaption = "SubjectList"
targetCaption = "Selected Subject"
listWidth = "170px"
listHeight = "120px"
orderable = "true">
<f:selectItems value = "#{managedBean.subjectList}"
itemValue = "#{subject}" itemLabel = "#{subject.subjectName}"/>
</rich:pickList>
</h:form>
</h:body>
</html>我们需要修改managedBean.java文件以填充xhtml文件中的列表组件.以下是我们修改过的Java文件的快照.
import java.util.Arrays;
import java.util.List;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.RequestScoped;
@ManagedBean
@RequestScoped
public class managedBean {
String message;
String job;
private List<String> SubjectList = Arrays.asList(
"Richface","AJAX","JAVA","JSF","DOTNET","python");
public String getMessage() {
return message;
}
public void setMessage(String message) {
System.out.println("setMessage method is getting called with--"+message);
this.message = message;
}
public String getJob() {
return job;
}
public void setJob(String job) {
System.out.println("setJob method is getting called with--"+job);
this.job = job;
}
public List<String> getSubjectList() {
return SubjectList;
}
public void setSubjectList(List<String> SubjectList) {
this.SubjectList = SubjectList;
}
}上面的代码将在浏览器中产生以下输出. pickList标记的"value"属性只是bean类的"getSubjectList()". "itemValue"是对象类的缩写，对应的"itemLabel"是实例值名称.在此示例中，我们的pickList标记自动创建两个名为"sourceCaption"和"targetCaption"的单独列表.属性可订购用于维护目标列表中的选择顺序.
此标记用于整体呈现列表. < orderingList>将自动提供一些按钮，如通过列表传播的功能，它有助于订购所选项目.在下面的示例中，我们将使用以下代码为"OrderingListExample.xhtml"创建一个orderingList.
<?xml version = "1.0" encoding = "UTF-8"?>
<!DOCTYPE html>
<html 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:a4j = "http://richfaces.org/a4j"
xmlns:rich = "http://richfaces.org/rich">
<h:head>
<title>OrderingList Example</title>
</h:head>
<h:body>
<h:form>
<h:outputText value = "ordering List Example"/><br/><br/>
<rich:orderingList value = "#{managedBean.subjectList}"
itemValue = "#{subject}"
itemLabel = "#{subject.subjectName}" >
</rich:orderingList>
</h:form>
</h:body>
</html>我们不需要更改我们的bean类，因为我们使用不同的标记为不同的表示再次填充相同的列表.与前面的示例一样，即使在这里，值属性也会保留整个列表来自"getSubjectList()". "itemValue"和"itemLabel"分别保存对象类和相应实例变量的值.
上面的代码将在浏览器中生成以下输出.
ListShuttle标签在RichFaces 3中可用.它有助于传播一个列表并将相同的值放入另一个列表中.在RichFaces 4中，此标记已被抑制，因为另一个名为< rich:pickList>的新标记可以实现相同的功能.如上所述.如果您使用的是RichFaces 3.0，则可以按以下方式使用此标记.
<rich:listShuttle sourceValue = "#{toolBar.freeItems}"
targetValue = "#{toolBar.items}" var = "items" listsHeight = "150"
sourceListWidth = "130" targetListWidth = "130"
sourceCaptionLabel = "Available Items"
targetCaptionLabel = "Currently Active Items"
converter = "listShuttleconverter">
<rich:column width = "18">
<h:graphicImage value = "#{items.iconURI}"></h:graphicImage>
</rich:column>
<rich:column>
<h:outputText value = "#{items.label}"></h:outputText>
</rich:column>
<a4j:support event = "onlistchanged" reRender = "toolBar" />
<a4j:support event = "onorderchanged" reRender = "toolBar" />
</rich:listShuttle>使用pickList而不是使用此标签非常方便，因为只需编写两行代码就可以使用pickList实现相同的功能.
