dangerframe2.java

里面包含了多个java的编程示例！而且举出初学者常常遇到的错误！

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

public class DangerFrame2 extends JFrame {
    JSlider speed;
    
    public DangerFrame2() {
        super("Warning!");
        setSize(400, 100);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        BorderLayout border = new BorderLayout();
        setLayout(border);
        // set up the speed slider
        speed = new JSlider(1, 100, 20);
        add(speed, BorderLayout.NORTH);
        // set up the danger panel
        Danger2 gb = new Danger2("Core Breach in Sector 12", this);
        add(gb, BorderLayout.CENTER);
        setVisible(true);
    }

    public static void main(String[] arguments) {
        DangerFrame2 frame = new DangerFrame2();
    }
}