丁又专老师第二次作业

import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Color;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

class TestMain extends JFrame
{
    private JPanel pane = null; // 主要的JPanel，该JPanel的布局管理将被设置成CardLayout
    private JPanel p = null; // 放按钮的JPanel
    private CardLayout card = null; // CardLayout布局管理器
    private JButton button_1 = null; // 显示图片
    private JPanel p_1 = null, p_2 = null, p_3 = null, p_4 = null, p_5 = null; // 要切换的三个JPanel

    public TestMain()
    {
        super("随机图片，显示次数");

        card = new CardLayout(5, 5);
        pane = new JPanel(card); // JPanel的布局管理将被设置成CardLayout
        p = new JPanel(); // 构造放按钮的JPanel
        button_1 = new JButton("随即图片");
        p.add(button_1);

        p_1 = new JPanel();
        p_2 = new JPanel();
        p_3 = new JPanel();
        p_4 = new JPanel();
        p_5 = new JPanel();

        p_1.setBackground(Color.RED);
        p_2.setBackground(Color.GREEN);
        p_3.setBackground(Color.YELLOW);
        p_4.setBackground(Color.BLUE);
        p_5.setBackground(Color.ORANGE);

        p_1.add(new JLabel("图片1"));
        p_2.add(new JLabel("图片2"));
        p_3.add(new JLabel("图片3"));
        p_4.add(new JLabel("图片4"));
        p_5.add(new JLabel("图片5"));

        pane.add(p_1, "1");
        pane.add(p_2, "2");
        pane.add(p_3, "3");
        pane.add(p_4, "4");
        pane.add(p_5, "5");

        button_1.addActionListener(new ActionListener()
        { // 上一步的按钮动作
            public void actionPerformed(ActionEvent e)
            {
                System.out.println(String.valueOf((int)Math.rint(1 + Math.random() * 4)));
                card.show(pane, String.valueOf((int)Math.rint(1 + Math.random() * 4)));
            }
        });
        this.getContentPane().add(pane);
        this.getContentPane().add(p, BorderLayout.SOUTH);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setSize(600, 400);
        this.setVisible(true);
    }

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

}