java - 在 Swing 应用程序中仅显示一个选定或请求的 jpanel

Question

我正在swing申请。我有 20 多个 jpanel。我想显示我想要显示的那个 jpanel :

例如:

WelcomePanel welcomePanel = new WelcomePanel();
BindingDetailsPanel bindingDetailsPanel = new BindingDetailsPanel();
FooterMainPanel footerMainPanel = new FooterMainPanel();
KeyMessageSetupPanel keyMessageSetupPanel = new KeyMessageSetupPanel();
SMSCSetupPanel sMSCSetupPanel = new SMSCSetupPanel();
LiveProcessorDetailsPanel runTimePanel = new LiveProcessorDetailsPanel();
RuntTimeInformationPanel welcomePanel=new RuntTimeInformationPanel();
BlockedSmscDetailsPanel blockedSmscDetailsPanel = new BlockedSmscDetailsPanel();

我正在我的主 jFrame 中制作上面列出的面板的对象。它工作正常

因为 :

public mainFrame(){
    requestResponseReportPanel.setVisible(false);
    keyMessageSetupPanel.setVisible(false);
    sMSCSetupPanel.setVisible(false);
    welcomePanel.setVisible(true);
    keyMessageDetailsPanel.setVisible(false);
    blockedSmscDetailsPanel.setVisible(false);
    runTimePanel.setVisible(false);
}

我的应用程序第一次启动时，它只会显示一个面板欢迎面板，我将其设置为可见 welcomePanel.setVisible(true);我有菜单，如果我点击它应该显示 keyMessageSetupPanel以下是显示此面板的代码:

private void keyMessageSetupMenuItemActionPerformed(java.awt.event.ActionEvent evt) {                                                        
    try {
        mainFrameContentPanel.add(keyMessageSetupPanel, BorderLayout.CENTER);
        keyMessageSetupPanel.setVisible(true);
        sMSCSetupPanel.setVisible(false);
        welcomePanel.setVisible(false);
        homeButton.setVisible(true);
        bindingDetailsPanel.setVisible(false);
        requestResponseReportPanel.setVisible(false);
        keyMessageDetailsPanel.setVisible(false);
        blockedSmscDetailsPanel.setVisible(false);
    } catch (Exception e) {
      printStackTrace();
    }
}   

我的问题是，如果我这样使用，我的应用程序正在运行。但它在运行时加载所有面板并且需要很长时间才能加载。如果我不喜欢这个，它会显示 welcomePanel如果我通过单击( menu 或 button )进入另一个面板:

示例 :

欢迎面板显示

我去了keyMessageSetupPanel (这工作正常)

现在我去了bindingDetailsPanel (有效)

但问题是我想再次keyMessageSetupPanel (它不会隐藏 bindingDetailsPanel )。

已编辑 这是显示 bindingDetailsPanel 的代码

mainFrameContentPanel.add(bindingDetailsPanel, BorderLayout.CENTER);
bindingDetailsPanel.setVisible(true);
keyMessageSetupPanel.setVisible(false);
sMSCSetupPanel.setVisible(false);
welcomePanel.setVisible(false);
homeButton.setVisible(true);
requestResponseReportPanel.setVisible(false);
keyMessageDetailsPanel.setVisible(false);
blockedSmscDetailsPanel.setVisible(false);

请帮帮我。
备注 如果您在不理解我的问题的地方不理解评论，我会尽力解释。

谢谢

Answer 1

您的代码不起作用的基本原因是您没有调用 revalidate()和 repaint()在进行交换后保存交换 JPanel 的容器上。这些调用告诉布局管理器重新布局所持有的组件，并告诉重绘管理器重绘容器及其子项。

话虽如此，在容器中交换可见组件的更好方法是使用为此明确构建的 CardLayout。

例如，请看这里:https://stackoverflow.com/a/6176115/522444

对于上述程序的另一个示例，这次有一些更好的关注点分离:

import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.*;
import java.util.ArrayList;
import java.util.List;

import javax.swing.*;

class MainClass implements ReceiveAction {
   private JPanel mainPanel = new JPanel();
   private JMenuBar menuBar = new JMenuBar();
   private JMenu chooseViewMenu = new JMenu("Choose View");

   public MainClass() {
      Registration registration = new Registration();
      ButtonPanel buttonPanel = new ButtonPanel();

      ReceiveAction[] recActions = {this, buttonPanel};
      new ViewSwapControl(registration, recActions);

      buttonPanel.setBorder(BorderFactory.createTitledBorder("Button Panel"));
      registration.setBorder(BorderFactory.createTitledBorder("Registration Panel"));

      mainPanel.setLayout(new BorderLayout());
      mainPanel.add(registration, BorderLayout.CENTER);
      mainPanel.add(buttonPanel, BorderLayout.SOUTH);

      menuBar.add(chooseViewMenu);
   }

   public JComponent getMainPanel() {
      return mainPanel;
   }

   public JMenuBar getMenuBar() {
      return menuBar ;
   }

   @Override
   public void addAction(Action action) {
      chooseViewMenu.add(new JMenuItem(action));
   }

   private static void createAndShowUI() {
      MainClass mainInstance = new MainClass();


      JFrame frame = new JFrame("Registration");
      frame.getContentPane().add(mainInstance.getMainPanel());
      frame.setJMenuBar(mainInstance.getMenuBar());
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.pack();
      frame.setLocationRelativeTo(null);
      frame.setVisible(true);
   }

   public static void main(String[] args) {
      java.awt.EventQueue.invokeLater(new Runnable() {
         public void run() {
            createAndShowUI();
         }
      });
   }

}

class ViewSwapControl {
   private Registration registration;
   private List<Action> actionList = new ArrayList<>(); 

   public ViewSwapControl(Registration registration, ReceiveAction... recActions) {
      this.registration = registration;
      for (final String keyText : Registration.KEY_TEXTS) {
         actionList.add(new MyAction(keyText));
      }
      for (ReceiveAction receiveAction : recActions) {
         for (Action action : actionList) {
            receiveAction.addAction(action);
         }
      }
   }

   @SuppressWarnings("serial")
   private class MyAction extends AbstractAction {
      public MyAction(String name) {
         super(name);
      }

      @Override
      public void actionPerformed(ActionEvent evt) {
         if (registration != null) {
            registration.swapView(getValue(NAME).toString());
         }
      }
   }

}

interface ReceiveAction {
   public void addAction(Action action);
}

@SuppressWarnings("serial")
class ButtonPanel extends JPanel implements ReceiveAction {

   public ButtonPanel() {
      setLayout(new GridLayout(1, 0, 10, 0));
   }

   @Override
   public void addAction(Action action) {
      add(new JButton(action));
   }
}

@SuppressWarnings("serial")
class Registration extends JPanel {
   // use these same constants as button texts later
   private static final Dimension PREF_SIZE = new Dimension(450, 300);
   public static final String USER_AGREEMENT = "User Agreement";
   public static final String USER_INFO = "User Information";
   public static final String ENROLLMENT = "Enrollment";
   // we'll extract them from this array
   public static final String[] KEY_TEXTS = {USER_AGREEMENT, USER_INFO, ENROLLMENT};
   private CardLayout cardlayout = new CardLayout();
   private JPanel cards = new JPanel(cardlayout);

   public Registration() {
      cards.add(createUserAgreePanel(), USER_AGREEMENT);
      cards.add(createUserInfoPanel(), USER_INFO);
      cards.add(createEnrollmentPanel(), ENROLLMENT);
      setLayout(new BorderLayout());
      add(cards, BorderLayout.CENTER);
   }

   @Override
   public Dimension getPreferredSize() {
      return PREF_SIZE;
   }

   private JPanel createEnrollmentPanel() {
      JPanel enrol = new JPanel();
      enrol.add(new JLabel("Enrollment"));
      return enrol;
   }

   private JPanel createUserAgreePanel() {
      JPanel userAgree = new JPanel();
      userAgree.add(new JLabel("User Agreement"));
      return userAgree;
   }

   private JPanel createUserInfoPanel() {
      JPanel userInfo = new JPanel();
      userInfo.add(new JLabel("User Information"));
      return userInfo;
   }

   public void swapView(String key) {
      cardlayout.show(cards, key);
   }

}