清除JFrame的组件并添加新组件

Question

我有JFrame，有一些选项。当按下确定按钮时，我希望相同的JFrame清除内容并添加新内容。我已经尝试过，但问题是新的JFrame被弹出。我做错了什么？

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.IOException;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.*;

public class GuiFrame extends JFrame {

    final JFrame f = new JFrame("Test");

    public void Starter(){
        ImageIcon img = new ImageIcon("C:\\Users\\neal\\Desktop\\no.png");
        f.setIconImage(img.getImage());
        ButtonGroup group = new ButtonGroup();
        final JRadioButton Acess = new JRadioButton("Acess");
        final JRadioButton Chat = new JRadioButton("Chat");
        group.add(Acess);
        group.add(Chat);
        f.setSize(400,100);
        f.setLocationRelativeTo(null);
        JButton OptionOk = new JButton("OK");

Label option = new Label("Choose a Option");

        final Container content = f.getContentPane();
        content.setBackground(Color.white);
        content.setLayout(new FlowLayout());

        content.add(option);
        content.add(Acess);
        content.add(Chat);
        content.add(OptionOk);
          f.setVisible(true);
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

              OptionOk.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent e) {


                try {
                    new GuiFrame().Initiate();
                } catch (UnknownHostException ex) {
                    Logger.getLogger(GuiFrame.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
              });
    }

    public void Initiate() throws UnknownHostException {

        f.removeAll();
        ButtonGroup group = new ButtonGroup();

        final JRadioButton ButtonServer = new JRadioButton("Server");
        final JRadioButton ButtonClient = new JRadioButton("Client");
        group.add(ButtonServer);
        group.add(ButtonClient);

        f.setSize(400, 100);
        f.setLocationRelativeTo(null);
        InetAddress thisIp = InetAddress.getLocalHost();

        ImageIcon img = new ImageIcon("C:\\Users\\neal\\Desktop\\no.png");
        f.setIconImage(img.getImage());
        Label lip = new Label("Your IP is : " + thisIp.getHostAddress());
        Label setup = new Label("Setup as ");
        JButton ButtonOk = new JButton("OK");

        final Container content = f.getContentPane();
        content.setBackground(Color.white);
        content.setLayout(new FlowLayout());
        content.add(lip);
        content.add(setup);
        content.add(ButtonServer);
        content.add(ButtonClient);
        content.add(ButtonOk);
        f.setVisible(true);
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

    public static void main(String[] args) throws UnknownHostException {

        GuiFrame gf = new GuiFrame();
        gf.Starter();
    }
}

Answer 1

解决方案很简单：使用CardLayout让这个布局管理器为您完成所有繁重的工作。有关如何执行此操作的详细信息，请参阅教程：How to use CardLayout

至于你的代码，请注意你实际上在启动时创建2个JFrame，如果按下JButton则再创建两个JFrame：

GuiFrame类本身扩展了JFrame，但它似乎是一个你永远不会使用的JFrame，因此被浪费了，但它在程序启动时以及每当创建GuiFrame实例时创建，例如按下按钮时。然后在这个类的内部创建另一个JFrame f，一个在程序启动时再次按下按钮，我不认为这是你想要做的。

因此，更改代码以使类不扩展JFrame，并且不要在按钮的ActionListener中创建类的新实例。而是使用CardLayout交换视图。

例如：

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;

public class GuiFrame {

   private static final String FIRST_PANEL = "First Panel";
   private static final String SECOND_PANEL = "Second Panel";
   final JFrame f = new JFrame("Test");
   private CardLayout cardLayout = new CardLayout();
   private JPanel content;

   public void Starter() {
      f.setSize(400, 100);
      f.setLocationRelativeTo(null);
      JButton OptionOk = new JButton("OK");

      Label option = new Label("Choose a Option");

      content = (JPanel) f.getContentPane();
      content.setLayout(cardLayout);

      JPanel firstPanel = new JPanel();
      firstPanel.setBackground(Color.white);
      firstPanel.setLayout(new FlowLayout());

      firstPanel.add(option);
      firstPanel.add(OptionOk);

      content.add(firstPanel, FIRST_PANEL);
      content.add(createSecondPanel(), SECOND_PANEL);
      f.setVisible(true);
      f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

      OptionOk.addActionListener(new ActionListener() {

         public void actionPerformed(ActionEvent e) {

            cardLayout.show(content, SECOND_PANEL);

         }
      });

   }

   private JPanel createSecondPanel() {
      JPanel secondPanel = new JPanel();
      secondPanel.add(new JButton(new AbstractAction("Go Back") {
         public void actionPerformed(ActionEvent e) {
            cardLayout.show(content, FIRST_PANEL);
         }
      }));
      return secondPanel;
   }


   public static void main(String[] args) {

      GuiFrame gf = new GuiFrame();
      gf.Starter();
   }

}

Answer 2

修复（但仍然很脏）版本：

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.*;

public class GuiFrame implements ActionListener{

    final JFrame f = new JFrame("Test");

    public void start(){
        ImageIcon img = new ImageIcon("C:\\Users\\neal\\Desktop\\no.png");
        f.setIconImage(img.getImage());
        ButtonGroup group = new ButtonGroup();
        final JRadioButton Acess = new JRadioButton("Acess");
        final JRadioButton Chat = new JRadioButton("Chat");
        group.add(Acess);
        group.add(Chat);
        f.setSize(400,100);
        f.setLocationRelativeTo(null);
        JButton OptionOk = new JButton("OK");

        Label option = new Label("Choose a Option");

        final Container content = f.getContentPane();
        content.setBackground(Color.white);
        content.setLayout(new FlowLayout());

        content.add(option);
        content.add(Acess);
        content.add(Chat);
        content.add(OptionOk);
        f.setVisible(true);
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        OptionOk.addActionListener(this);

    }

    public void initiate() throws UnknownHostException {

        //f.removeAll();
        ButtonGroup group = new ButtonGroup();

        final JRadioButton ButtonServer = new JRadioButton("Server");
        final JRadioButton ButtonClient = new JRadioButton("Client");
        group.add(ButtonServer);
        group.add(ButtonClient);

        f.setSize(400, 100);
        f.setLocationRelativeTo(null);
        InetAddress thisIp = InetAddress.getLocalHost();

        ImageIcon img = new ImageIcon("C:\\Users\\neal\\Desktop\\no.png");
        f.setIconImage(img.getImage());
        Label lip = new Label("Your IP is : " + thisIp.getHostAddress());
        Label setup = new Label("Setup as ");
        JButton ButtonOk = new JButton("OK");



        final Container content = f.getContentPane();
        content.removeAll();
        content.setBackground(Color.white);
        content.setLayout(new FlowLayout());
        content.add(lip);
        content.add(setup);
        content.add(ButtonServer);
        content.add(ButtonClient);
        content.add(ButtonOk);
        f.repaint();

    }

    public void actionPerformed(ActionEvent arg0) {
        try {
            initiate();
        } catch (UnknownHostException ex) {
            Logger.getLogger(GuiFrame.class.getName()).log(Level.SEVERE, null, ex);
        }       
    }

    public static void main(String[] args) throws UnknownHostException {

        GuiFrame gf = new GuiFrame();
        gf.start();
    }
}