Question

当你点击View tables并查看全部时，我在java中有这个程序出现一个窗口，我需要隐藏第一个窗口，然后关闭第二个窗口，

第一个再次可见

我不知道如何从这些类中引用一个对象，因为我已经创建了它们 new Main（）;和新的View（）; ：）

这是一个类：

package CarManager;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;

public class Main extends JFrame {

    private static final long serialVersionUID = 1L;
    static int width = 400;
    static int height = width / 16 * 9;
    static String title = "Car Manager";
    JButton viewTables = new JButton("View tables");
    JButton clients = new JButton("Clients");
    JButton search = new JButton("Search");
    JButton viewCars = new JButton("View all");
    JButton viewRent = new JButton("Rent a car");
    JButton viewBuy = new JButton("Buy a car");
    JButton viewAccessory = new JButton("Accessory");

    public Main() {

        setLayout(null);
        setLocationRelativeTo(null);
        setTitle(title);
        setSize(width, height);
        setResizable(false);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setVisible(true);

        JLabel background = new JLabel(new ImageIcon("res\\background2.jpg"));
        add(background);
        background.setSize(width, height);
        add(viewTables);
        add(clients);
        add(search);
        viewTables.setBounds(20, 20, 110, 30);
        clients.setBounds(20, 70, 110, 30);
        search.setBounds(20, 120, 110, 30);

        viewTables.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                add(viewCars);
                viewCars.setBounds(260, 20, 110, 20);

                add(viewRent);
                viewRent.setBounds(260, 50, 110, 20);

                add(viewBuy);
                viewBuy.setBounds(260, 80, 110, 20);

                add(viewAccessory);
                viewAccessory.setBounds(260, 110, 110, 20);
            }
        });

        viewCars.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                new View();
                setVisible(false);
            }
        });

    }

    public static void main(String args[]) {
        new Main();
    }
}

这是出现的第二个窗口：

package CarManager;

import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;

public class View extends JFrame {

    private static final long serialVersionUID = 1L;
    int width = 400;
    int height = width / 16 * 9;
    String title = "View all Cars";

    public View() {
        setLayout(null);
        setLocationRelativeTo(null);
        setTitle(title);
        setSize(width, height);
        setResizable(false);
        setDefaultCloseOperation(DISPOSE_ON_CLOSE);
        setVisible(true);
        JLabel background = new JLabel(new ImageIcon("res\\background2.jpg"));
        add(background);
        background.setSize(width, height);
    }
}

我需要的是当我关闭第二个窗口时第一个窗口再次可见

Answer 1

import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import java.awt.event.*;


class View extends JFrame  {

private static final long serialVersionUID = 1L;
int width = 400;
int height = width / 16 * 9;
String title = "View all Cars";

    public View() {
    setLayout(null);
    setLocationRelativeTo(null);
    setTitle(title);
    setSize(width, height);
    setResizable(false);
    setDefaultCloseOperation(DISPOSE_ON_CLOSE);
    setVisible(true);
    JLabel background = new JLabel(new ImageIcon("res\\background2.jpg"));
    add(background);
    background.setSize(width, height);
   WindowListener listener = new WindowAdapter() {


   public void windowClosing(WindowEvent w) {

          new Main();

       }

      };

     addWindowListener(listener);
      }
    }

请运行程序view.java我添加Windows Adapter以在窗口关闭时获取Windows事件，然后main（）窗口显示

Answer 2

您可以创建自己的WindowAdapter：

public class MyWindowAdapter extends WindowAdapter {

    private Main mainFrame;         

    public MyWindowAdapter(Main mainFrame) {   // when creating an instance of this WindowAdapter, tell it with which Main Window you are working with
        this.mainFrame = mainFrame;
    }

    public void windowClosing(WindowEvent e) {
        mainFrame.setVisible(true);                 // when this WindowAdapter registers a closing operation it will set the Main Window visible again
    }
}

然后当您在View中创建新的actionPerformed()时，您注册了一个自己的WindowAdapter的新实例，并告诉窗口适配器您的Main实例是什么样的。

 viewCars.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            View view = new View();                         // your new View
            view.addWindowListener(new MyWindowAdapter(Main.this));   // register the WindowAdapter to your new View
            setVisible(false);
        }
    });

处理窗口的事件

2 个答案: