我的代码：
package a2048;
import javax.swing.JFrame;
public class GameWindow extends JFrame {
public GameWindow() {
add(new Main());
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(409, 435);
setLocationRelativeTo(null);
setTitle("2048");
setResizable(true);
setVisible(true);
}
public static void main(String[] args) {
new GameWindow();
}
}
这是一个类，另一个是：
package a2048;
import java.util.*;
import java.awt.event.*;
import javax.swing.*;
import java.awt.*;
public class Main extends JPanel implements MouseListener
{
int randx, randy, quit;
int a1, a2, a3, a4, b1, b2, b3 ,b4, c1, c2, c3, c4, d1, d2, d3, d4;
int GetRandom(int min, int max)
{
int range = (max - min) + 1;
double rand = (Math.random() * range) + min;
return (int) rand;
}
public Main()
{
setBackground(Color.BLACK);
setDoubleBuffered(true);
}
public void paint(Graphics g)
{
quit = 0;
a1 = a2 = a3 = a4 = b1 = b2 = b3 = b4 = c1 = c2 = c3 = c4 = d1 = d2 = d3 = d4 = 0;
super.paint(g);
Graphics2D g2d = (Graphics2D)g;
g2d.setColor(Color.white);
g2d.drawLine(0, 0, 500, 0);
g2d.drawLine(0, 100, 500, 100);
g2d.drawLine(0, 200, 500, 200);
g2d.drawLine(0, 300, 500, 300);
g2d.drawLine(0, 400, 500, 400);
g2d.drawLine(0, 0, 0, 500);
g2d.drawLine(100, 0, 100, 500);
g2d.drawLine(200, 0, 200, 500);
g2d.drawLine(300, 0, 300, 500);
g2d.drawLine(400, 0, 400, 500);
Font myFont = new Font("TimesRoman", Font.PLAIN, 75);
g2d.setFont(myFont);
while(quit == 0)
{
randx = GetRandom(1, 4);
randy = GetRandom(1, 4);
if(randx == 1)
{
if(randy == 1 && a1 == 0)
{
a1 = 2;
}
else if(randy == 2 && a2 == 0)
{
a2 = 2;
}
else if(randy == 3 && a3 == 0)
{
a3 = 2;
}
else if(randy == 4 && a4 == 0)
{
a4 = 2;
}
}
else if(randx == 2)
{
if(randy == 1 && b1 == 0)
{
b1 = 2;
}
else if(randy == 2 && b2 == 0)
{
b2 = 2;
}
else if(randy == 3 && b3 == 0)
{
b3 = 2;
}
else if(randy == 4 && b4 == 0)
{
b4 = 2;
}
}
else if(randx == 3)
{
if(randy == 1 && c1 == 0)
{
c1 = 2;
}
else if(randy == 2 && c2 == 0)
{
c2 = 2;
}
else if(randy == 3 && c3 == 0)
{
c3 = 2;
}
else if(randy == 4 && c4 == 0)
{
c4 = 2;
}
}
else if(randx == 4)
{
if(randy == 1 && d1 == 0 && a1 == 0)
{
d1 = 2;
}
else if(randy == 2 && d2 == 0 && a1 == 0)
{
d2 = 2;
}
else if(randy == 3 && d3 == 0 && a1 == 0)
{
d3 = 2;
}
else if(randy == 4 && d4 == 0 && a1 == 0)
{
d4 = 2;
}
}
if(a1 > 0)
g2d.drawString(String.valueOf(a1), (randx * 100) - 70, (randy * 100) - 25);
if(a2 > 0)
g2d.drawString(String.valueOf(a2), (randx * 100) - 70, (randy * 100) - 25);
if(a3 > 0)
g2d.drawString(String.valueOf(a3), (randx * 100) - 70, (randy * 100) - 25);
if(a4 > 0)
g2d.drawString(String.valueOf(a4), (randx * 100) - 70, (randy * 100) - 25);
if(b1> 0)
g2d.drawString(String.valueOf(b1), (randx * 100) - 70, (randy * 100) - 25);
if(b2 > 0)
g2d.drawString(String.valueOf(b2), (randx * 100) - 70, (randy * 100) - 25);
if(b3 > 0)
g2d.drawString(String.valueOf(b3), (randx * 100) - 70, (randy * 100) - 25);
if(b4 > 0)
g2d.drawString(String.valueOf(b4), (randx * 100) - 70, (randy * 100) - 25);
if(c1 > 0)
g2d.drawString(String.valueOf(c1), (randx * 100) - 70, (randy * 100) - 25);
if(c2 > 0)
g2d.drawString(String.valueOf(c2), (randx * 100) - 70, (randy * 100) - 25);
if(c3 > 0)
g2d.drawString(String.valueOf(c3), (randx * 100) - 70, (randy * 100) - 25);
if(c4 > 0)
g2d.drawString(String.valueOf(c4), (randx * 100) - 70, (randy * 100) - 25);
if(d1 > 0)
g2d.drawString(String.valueOf(d1), (randx * 100) - 70, (randy * 100) - 25);
if(d2 > 0)
g2d.drawString(String.valueOf(d2), (randx * 100) - 70, (randy * 100) - 25);
if(d3 > 0)
g2d.drawString(String.valueOf(d3), (randx * 100) - 70, (randy * 100) - 25);
if(d4 > 0)
g2d.drawString(String.valueOf(d4), (randx * 100) - 70, (randy * 100) - 25);
quit = 1;
}
Toolkit.getDefaultToolkit().sync();
g.dispose();
}
public void mouseExited(MouseEvent e)
{
repaint();
}
public void mouseReleased(MouseEvent e)
{
repaint();
}
public void mousePressed(MouseEvent e)
{
repaint();
}
public void mouseEntered(MouseEvent e)
{
repaint();
}
public void mouseClicked(MouseEvent e)
{
a1 = 5;
repaint();
}
}
我不明白为什么当我点击窗口时mouseClicked方法没有做任何事情。我想要它做的是设置a1到5，然后在屏幕上打印，但它只是没有做任何事情。如何改变它以使MouseListener正常工作？
答案 0 :(得分：2)
MouseListener需要注册 的内容才能执行任何操作。
每当你在某个东西上单击鼠标时，它就会生成一个MouseEvent并在正在侦听它的任何东西上调用方法，并将该事件作为参数传递。
您似乎是在JPanel中实现您的侦听器，因此除了将其添加为GameWindow中的组件之外，您还需要在窗口中将其注册为鼠标侦听器
替换
add(new Main());
与
Main main = new Main();
addMouseListener(main);
add(main);
编辑
HovercraftFullOfEels建议的更清洁的方法就是拥有
主要 JPanel自行侦听鼠标事件。为此，您可以在Main的构造函数中调用addMouseListener()，而不是在封闭的JFrame中调用：
public Main() {
addMouseListener(this);
setBackground(Color.BLACK);
setDoubleBuffered(true);
}