这是从Jpanel扩展的子类。目前我没有主要的驱动程序，即Jpanel。你能帮我创一个吗？
这是该程序的子类，它显示了当用户单击applet时滚动的一对骰子。
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
/**
* Shows a pair of dice that are rolled when the user clicks on the
* applet. It is assumed that the panel is 100-by-100 pixels.
*/
public class DicePanel extends JPanel {
private int die1 = 4; // The values shown on the dice.
private int die2 = 3;
/**
* The constructor adds a mouse listener to the panel. The listener
* will roll the dice when the user clicks the panel. Also, the
* background color and the preferred size of the panel are set.
*/
public DicePanel() {
setPreferredSize( new Dimension(100,100) );
setBackground( new Color(200,200,255) ); // light blue
addMouseListener( new MouseAdapter() {
public void mousePressed(MouseEvent evt) {
roll();
}
});
}
/**
* Draw a die with upper left corner at (x,y). The die is
* 35 by 35 pixels in size. The val parameter gives the
* value showing on the die (that is, the number of dots).
*/
private void drawDie(Graphics g, int val, int x, int y) {
g.setColor(Color.white);
g.fillRect(x, y, 35, 35);
g.setColor(Color.black);
g.drawRect(x, y, 34, 34);
if (val > 1) // upper left dot
g.fillOval(x+3, y+3, 9, 9);
if (val > 3) // upper right dot
g.fillOval(x+23, y+3, 9, 9);
if (val == 6) // middle left dot
g.fillOval(x+3, y+13, 9, 9);
if (val % 2 == 1) // middle dot (for odd-numbered val's)
g.fillOval(x+13, y+13, 9, 9);
if (val == 6) // middle right dot
g.fillOval(x+23, y+13, 9, 9);
if (val > 3) // bottom left dot
g.fillOval(x+3, y+23, 9, 9);
if (val > 1) // bottom right dot
g.fillOval(x+23, y+23, 9,9);
}
/**
* Roll the dice by randomizing their values. Tell the
* system to repaint the applet, to show the new values.
*/
void roll() {
die1 = (int)(Math.random()*6) + 1;
die2 = (int)(Math.random()*6) + 1;
repaint();
}
/**
* The paintComponent method just draws the two dice and draws
* a one-pixel wide blue border around the panel.
*/
public void paintComponent(Graphics g) {
super.paintComponent(g); // fill with background color.
g.setColor( Color.BLUE );
g.drawRect(0,0,99,99);
g.drawRect(1,1,97,97);
drawDie(g, die1, 10, 10);
drawDie(g, die2, 55, 55);
}
} // end class DicePanel
答案 0 :(得分：3)
您只需向main添加DicePanel方法并将其包装在JFrame
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.event.MouseAdapter;
import javafx.scene.input.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class DicePanel extends JPanel {
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new DicePanel());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
private int die1 = 4; // The values shown on the dice.
private int die2 = 3;
/**
* The constructor adds a mouse listener to the panel. The listener will roll the dice when the user clicks the panel. Also, the background color and the
* preferred size of the panel are set.
*/
public DicePanel() {
setPreferredSize(new Dimension(100, 100));
setBackground(new Color(200, 200, 255)); // light blue
addMouseListener(new MouseAdapter() {
public void mousePressed(MouseEvent evt) {
roll();
}
});
}
/**
* Draw a die with upper left corner at (x,y). The die is 35 by 35 pixels in size. The val parameter gives the value showing on the die (that is, the number
* of dots).
*/
private void drawDie(Graphics g, int val, int x, int y) {
g.setColor(Color.white);
g.fillRect(x, y, 35, 35);
g.setColor(Color.black);
g.drawRect(x, y, 34, 34);
if (val > 1) // upper left dot
{
g.fillOval(x + 3, y + 3, 9, 9);
}
if (val > 3) // upper right dot
{
g.fillOval(x + 23, y + 3, 9, 9);
}
if (val == 6) // middle left dot
{
g.fillOval(x + 3, y + 13, 9, 9);
}
if (val % 2 == 1) // middle dot (for odd-numbered val's)
{
g.fillOval(x + 13, y + 13, 9, 9);
}
if (val == 6) // middle right dot
{
g.fillOval(x + 23, y + 13, 9, 9);
}
if (val > 3) // bottom left dot
{
g.fillOval(x + 3, y + 23, 9, 9);
}
if (val > 1) // bottom right dot
{
g.fillOval(x + 23, y + 23, 9, 9);
}
}
/**
* Roll the dice by randomizing their values. Tell the system to repaint the applet, to show the new values.
*/
void roll() {
die1 = (int) (Math.random() * 6) + 1;
die2 = (int) (Math.random() * 6) + 1;
repaint();
}
/**
* The paintComponent method just draws the two dice and draws a one-pixel wide blue border around the panel.
*/
public void paintComponent(Graphics g) {
super.paintComponent(g); // fill with background color.
g.setColor(Color.BLUE);
g.drawRect(0, 0, 99, 99);
g.drawRect(1, 1, 97, 97);
drawDie(g, die1, 10, 10);
drawDie(g, die2, 55, 55);
}
} // end class DicePanel
就个人而言，我会创建一个新的Main类，基本上做同样的事情
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Main {
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new DicePanel());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
}
这意味着您的DicePanel并未承担不必要的体重，并且您将程序限制为只有一个入口点......但那只是我......