我有一个 JFrame
,它有一个 Panel
,供 JButtons
在两个 JPanels
之间导航( >注册面板
和确认面板
)。两个JPanel
通过使用CardPanel/CardLayout
相互切换。当用户在 RegistrationPanel
中输入信息时,是否有办法将此信息返回到下面列出的 StartFrame
?
import java.awt.BorderLayout;
public class StartFrame extends JFrame implements ActionListener
{
JButton nextButton = new JButton("Next");
JButton previousButton = new JButton("Previous");
JButton registerButton = new JButton("Register");
JPanel cardPanel = new JPanel();
CardLayout cardLayout = new CardLayout(10, 10);
public StartFrame()
{
setLayout(new BorderLayout(5, 5));
nextButton.addActionListener(this);
previousButton.addActionListener(this);
previousButton.setVisible(false);
registerButton.addActionListener(this);
registerButton.setVisible(false);
Panel buttonsPanel = new Panel(new FlowLayout(FlowLayout.CENTER));
buttonsPanel.add(previousButton);
buttonsPanel.add(nextButton);
buttonsPanel.add(registerButton);
setCardLayout();
add(BorderLayout.SOUTH, buttonsPanel);
add(BorderLayout.CENTER, cardPanel);
}
private void setCardLayout()
{
cardPanel.setLayout(cardLayout);
cardPanel.add(new RegistrationPanel(), "registration");
cardPanel.add(new ConfirmationPanel(), "confirmation");
cardLayout.show(cardPanel, "registration");
}
@Override
public void actionPerformed(ActionEvent event)
{
if (event.getSource().equals(nextButton))
{
cardLayout.next(cardPanel);
previousButton.setVisible(true);
registerButton.setVisible(true);
nextButton.setVisible(false);
}
else
{
cardLayout.previous(cardPanel);
previousButton.setVisible(false);
registerButton.setVisible(false);
nextButton.setVisible(true);
}
}
}
最佳答案
这取决于谁在传递此信息中扮演“主动”角色。 RegistrationPanel 是否应该将信息传递回 StartFrame(例如,当单击 RegsitrationPanel 上的按钮时?)或者 StartFrame 是否应该从 RegistrationPanel 获取信息(例如,当 StartFrame 上的按钮被单击时)被点击)?
在第一种情况下,RegistrationPanel 需要对 StartFrame 的引用(最好以更“抽象”的形式,以避免对这个具体类的依赖)。在第二种情况下,StartFrame 需要引用 RegistrationPanel。
这里粗略地概述了这些方法:
对于第一种情况:
class RegistrationPanel
{
private StartFrame startFrame;
public RegistrationPanel(StartFrame startFrame)
{
this.startFrame = startFrame;
}
// Called e.g. when a button was clicked on this panel
void passBackInformationToStartFrame()
{
startFrame.setInfo(this.getInfo());
}
}
class StartFrame ...
{
...
private void setCardLayout()
{
cardPanel.setLayout(cardLayout);
// Remove:
//cardPanel.add(new RegistrationPanel(), "registration");
// Add:
cardPanel.add(new RegistrationPanel(this), "registration");
....
}
}
对于第二种情况
public class StartFrame extends JFrame implements ActionListener
{
...
private RegistrationPanel registrationPanel
private void setCardLayout()
{
cardPanel.setLayout(cardLayout);
// Remove:
//cardPanel.add(new RegistrationPanel(), "registration");
// Add:
registrationPanel = new RegistrationPanel();
cardPanel.add(registrationPanel, "registration");
}
// Called e.g. when a button is clicked on this frame:
void fetchInformationFromRegistrationPanel()
{
Info info = registrationPanel.getInfo();
...
}
关于java - 从 JPanel 返回信息,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/21354529/