我有一个数据表，每一行都有“编辑”和“删除”按钮。
它几乎类似于http://www.primefaces.org/showcase-labs/ui/datatableRowSelectionByColumn.jsf数据表。
单击“编辑”按钮时，如果使用<h:outputText>显示选定的行值，则这些值将正确显示。
但是，如果我想使用<h:inputText value="#{userCRUDMB.selectedUser.userName}"/>在输入文本字段中显示它，则会抛出错误，提示selectedUser is resolved as null。
如果我仅使用<h:outputText ...>，则userCRUDMB.selectedUser()方法将被正确调用。
但是，如果我在对话框中使用<h:inputText ...>，则根本不会调用setter方法。
我正在使用Mojarra 2.1.6，PrimeFaces 3.0，Apache Tomcat7.0.32。
知道为什么会这样吗？
代码：代码与http://www.primefaces.org/showcase-labs/ui/datatableRowSelectionByColumn.jsf相同，除了在对话框中而不是使用来显示文本外，我正在尝试使用在输入文本框中显示文本。
public class User
{
private Integer userId;
private String userName;
private String password;
private String firstname;
private String lastname;
private String email;
private Date dob;
private String gender;
//setters/getters
}
package com.sivalabs.primefacesdemo.managedbeans;
import java.util.ArrayList;
import java.util.List;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.RequestScoped;
import com.sivalabs.primefacesdemo.model.User;
import com.sivalabs.primefacesdemo.model.UserDataModel;
import com.sivalabs.primefacesdemo.service.SpringContainer;
import com.sivalabs.primefacesdemo.service.UserService;
@ManagedBean(name="UserCRUDMB")
@RequestScoped
public class UserCRUDMB
{
private UserDataModel userDataModel;
private User selectedUser;
private User[] selectedUsers;
public UserCRUDMB()
{
List<User> users = new ArrayList<User>();
for (int i = 0; i < 15; i++) {
User user = new User();
user.setUserId(i);
user.setUserName("userName"+i);
users.add(user);
}
this.userDataModel = new UserDataModel(users);
}
public UserDataModel getUserDataModel() {
return userDataModel;
}
public void setUserDataModel(UserDataModel userDataModel) {
this.userDataModel = userDataModel;
}
public User[] getSelectedUsers() {
return selectedUsers;
}
public void setSelectedUsers(User[] selectedUsers) {
this.selectedUsers = selectedUsers;
}
public User getSelectedUser() {
System.out.println("get-->"+selectedUser);
return selectedUser;
}
public void setSelectedUser(User selectedUser) {
System.out.println("set--->"+selectedUser);
this.selectedUser = selectedUser;
}
}
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<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:c="http://java.sun.com/jsp/jstl/core"
xmlns:p="http://primefaces.org/ui">
<h:head>
</h:head>
<body>
<h:form id="form">
<h:outputText value="PrimeFaces Demo - ShowUsers" />
<p:dataTable value="#{UserCRUDMB.userDataModel}" var="userObj"
selection="#{UserCRUDMB.selectedUsers}"
widgetVar="usersTbl">
<f:facet name="header">UserManagement</f:facet>
<p:column selectionMode="multiple"></p:column>
<p:column headerText="UserId">#{userObj.userId}</p:column>
<p:column headerText="UserName">#{userObj.userName}</p:column>
<p:column>
<p:commandButton value="Edit"
oncomplete="userEditDlg.show()"
update="form:userEditTbl">
<f:setPropertyActionListener target="#{UserCRUDMB.selectedUser}" value="#{userObj}"></f:setPropertyActionListener>
</p:commandButton>
</p:column>
<p:column>
<p:commandButton value="Delete" action="#{UserCRUDMB.deleteUser}"
update="usersTbl"
ajax="true">
<f:setPropertyActionListener target="#{UserCRUDMB.selectedUser}" value="#{userObj}"></f:setPropertyActionListener>
</p:commandButton>
</p:column>
<f:facet name="footer">
<p:commandButton value="Delete Selected" action="#{UserCRUDMB.deleteUsers}"
update="usersTbl"
ajax="true">
</p:commandButton>
</f:facet>
</p:dataTable>
<p:dialog widgetVar="userEditDlg" header="User Edit Form" hideEffect="explode"
minHeight="200" minWidth="300">
<h:panelGrid columns="2" id="userEditTbl" >
<h:outputLabel value="UserId" />
<h:outputText value="#{UserCRUDMB.selectedUser.userId}"/>
<h:outputLabel value="UserName" />
<h:inutText value="#{UserCRUDMB.selectedUser.userName}"/>
</h:panelGrid>
</p:dialog>
</h:form>
</body>
</html>
谢谢，
西瓦
最佳答案
如果使用的是Ajax，则请求范围不是“理想”范围，因为将为每个请求重新创建bean。这可能是selectedUser为空的原因。请改用视图范围（@ViewScoped）。