java - Netbeans 无法读取我的第二个表单

Question

我是 Java 新手，我的游戏主菜单有问题。我已经按照互联网上的信息进行操作，但仍然无法修复它。错误出现在我的主窗体中， public class Screen extends JFrame Implements ActionListener { 和 Start fram2 = new Start(); 请帮助我

这是我的代码: -- 主窗体

    package screen;
//import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import java.awt.FlowLayout;
import java.awt.event.ActionListener;
import java.awt.event.InputEvent;
import java.awt.event.KeyEvent;
import javax.swing.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
//import java.awt.event.InputEvent;
//import java.awt.event.KeyEvent;
import javafx.event.ActionEvent;

 public class Screen extends JFrame implements ActionListener {

    public Screen() {
    JFrame f = new JFrame("Menu Demo");
    f.setSize(800, 600);

    f.setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);
    JMenuBar jmb = new JMenuBar();

    JMenu jmFile = new JMenu("File");
    JMenuItem jmiOpen = new JMenuItem("Create Player");
    JMenuItem jmiClose = new JMenuItem("Close");

    JMenuItem jmiExit = new JMenuItem("Exit");
    JPanel p = new JPanel();
    //Container c = getContentPane();

     JButton start = new JButton("START!");
     JButton instructions = new JButton ("INSTRUCTIONS");
     JButton close = new JButton("CLOSE!");

      jmFile.setMnemonic(KeyEvent.VK_F);
      jmiOpen.setMnemonic(KeyEvent.VK_O);
      jmiClose.setMnemonic(KeyEvent.VK_S);
      jmiExit.setMnemonic(KeyEvent.VK_X);

      jmiOpen.setAccelerator(KeyStroke.getKeyStroke(
                KeyEvent.VK_O,
        InputEvent.CTRL_DOWN_MASK
        ));

      jmiClose.setAccelerator(KeyStroke.getKeyStroke(
                KeyEvent.VK_S,
        InputEvent.CTRL_DOWN_MASK
        ));

      jmiExit.setAccelerator(KeyStroke.getKeyStroke(
                KeyEvent.VK_X,
        InputEvent.CTRL_DOWN_MASK
        ));


    jmFile.add(jmiOpen);
    jmFile.add(jmiClose);

    jmFile.addSeparator();
    jmFile.add(jmiExit);
    jmb.add(jmFile);
    p.add(start);
      p.add(instructions);
      instructions.addActionListener(new ActionListener() 
{
    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == instructions){
        setVisible(false);
        //Start fram2 = new Start();  
       Start fram2 = new Start();
        dispose();
    }
    }
});

      p.add(close);  
      f.add(p,"South");

      start .addActionListener((ActionListener) this);
      instructions.addActionListener((ActionListener) this);
      close .addActionListener((ActionListener) this);

   // JMenu jmOptions = new JMenu("Options");
   // JMenu a = new JMenu("A");
   // JMenuItem b = new JMenuItem("B");
   // JMenuItem c = new JMenuItem("C");
    JMenuItem d = new JMenuItem("D");
   // a.add(b);
    //a.add(c);
   // a.add(d);
   // jmOptions.add(a);

    JMenu e = new JMenu("E");
    e.add(new JMenuItem("F"));
    e.add(new JMenuItem("G"));


    JMenu jmHelp = new JMenu("Help");
    JMenuItem jmiAbout = new JMenuItem("About");
    jmHelp.add(jmiAbout);
    jmb.add(jmHelp);

    jmiOpen.addActionListener((ActionListener) this);
    jmiClose.addActionListener((ActionListener) this);

    jmiExit.addActionListener((ActionListener) this);
    d.addActionListener((ActionListener) this);
    jmiAbout.addActionListener((ActionListener) this);

    f.setJMenuBar(jmb);
    f.setVisible(true);

    JLabel img = new JLabel(new ImageIcon("D:/SpaceShip.jpg"));
         f.add(img,"North");

    p.setLayout(new FlowLayout());
    }

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

    public void actionPerformed(ActionEvent arg0) { // try to use actionPerformed(java.awt.event.ActionEvent) but still has error
        // Do something here

    }

}

--二等

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

 class Start extends JFrame{
   JFrame fram2 = new JFrame("About");  

   public  Start(){

setSize(800,600);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

JLabel jl1 = new JLabel ("    ABOUT THE DEVELOPER   ");
JLabel jl2 = new JLabel ("3 Mahasiswa Sistem Informasi dari Universitas Tarumanagara");
JLabel jl3 = new JLabel ("Mereka adalah : ");
JLabel jl4 = new JLabel (" \t1. Meiliana Setiady, 825160021");
JLabel jl5 = new JLabel (" \t2. James Natasalim, 825160023");
JLabel jl6 = new JLabel (" \t3. Maya Retnosari, 825160030");
JLabel jl7 = new JLabel (" Selamat menikmati permainan dari kami ^__^");

JPanel p2 = new JPanel();
p2.add(jl1);
p2.add(jl2);
p2.add(jl3);
p2.add(jl4);
p2.add(jl5);
p2.add(jl6);
p2.add(jl7);
getContentPane().add(p2);
//fram2.add(p2);

//fram2.setSize(800,600);
setVisible(true);
}

}

第一种形式的包中仍然存在错误:(import java.awt.event.ActionListener; 导入 java.awt.event.InputEvent; 导入 java.awt.event.KeyEvent;) 并在“instructions.addActionListener(new ActionListener()”行中

红线表示: java.lang.ExceptionInInitializerError 引起原因:java.lang.RuntimeException:无法编译源代码 - 找不到符号 符号:ActionListener 类 位置:类java.awt.event 在 screen.Screen.(Screen.java:10) 线程“main”Java 中的异常返回:1 构建失败(总时间:1秒)

我错过了什么吗？

Answer 1

Screen is not abstract and does not override abstract method actionPerformed(java.awt.event.ActionEvent) in java.awt.event.ActionListener at screen.Screen.

您必须实现actionPerformed(java.awt.event.ActionEvent)方法

 @Override
    public void actionPerformed(ActionEvent arg0) {
        // Do something here

    }

在你的第二堂课中，

JLabel jl1 = new JLabel(" \tABOUT THE DEVELOPER\t", 30);

你不能有一个 int。它必须是以下常量之一

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