所以我一直在尝试用Java制作非常简单的游戏。当我在一个类中创建整个程序时,我一直在取得成功,但每当我尝试添加面向对象的原则时,一切都会崩溃。我想要的是从我的好人那里发射子弹,这或多或少是一个炮塔。我可以轻松地设置这样的东西,但当我尝试使用类来代表好人和子弹时,一切都崩溃了。 这是我到目前为止所拥有的。 设置主程序框架:
import javax.swing.JFrame;
public class Shooter
{
public static void main (String[] args)
{
JFrame frame = new JFrame("Car");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
ShooterPanel panel = new ShooterPanel();
frame.getContentPane().add(panel);
frame.pack();
frame.setVisible(true);
}
}
ShooterPanel类:
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class ShooterPanel extends JPanel
{
final int WIDTH = 200, HEIGHT = 100;
GoodGuy hero;
public ShooterPanel()
{
hero = new GoodGuy(0, HEIGHT-20, 20);
addKeyListener(new MoveListener());
setPreferredSize(new Dimension (WIDTH, HEIGHT));
setFocusable(true);
}
public void paintComponent(Graphics page)
{
super.paintComponent(page);
hero.draw(page);
}
private class MoveListener implements KeyListener
{
public void keyPressed (KeyEvent event)
{
switch (event.getKeyCode())
{
case KeyEvent.VK_SPACE:
hero.shoot();
break;
}
}
//--------------------------------------------------------------
//Provide empty definitions for unused event methods.
//--------------------------------------------------------------
public void keyTyped (KeyEvent event) {}
public void keyReleased (KeyEvent event) {}
}
}
我们的主角:
import java.awt.*;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
public class GoodGuy
{
private int x, y, size;
private Bullet bullet;
public GoodGuy(int x, int y, int height)
{
size = height;
this.x = x;
this.y = y;
}
public int getSize()
{
return size;
}
public void draw(Graphics page)
{
page.drawRect(x, y, size, size);
}
public void shoot()
{
bullet = new Bullet(x+size, y);
}
}
他的子弹:
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.Timer;
public class Bullet
{
private int x, y;
final int LENGTH = 5, DELAY =200;
private Timer timer;
Graphics page1;
public Bullet(int x, int y)
{
this.x = x;
this.y = y;
timer = new Timer(DELAY, new BulletListener());
timer.start();
}
public void draw(Graphics page)
{
page.drawLine (x, y, x+LENGTH, y);
}
//*****************************************************************
// Represents the action listener for the timer.
//*****************************************************************
private class BulletListener implements ActionListener
{
public void actionPerformed (ActionEvent event)
{
x +=5;
draw(page1);
}
}
}
我想要发生的是空格键被按下,子弹出现在好人身上,并且它会在屏幕上向右移动。我根本无法得到子弹。我尝试了几件事,都无济于事。我确信这很容易。正如我所说,我可以在我的ShooterPanel类中使用变量来绘制子弹而不是创建对象,但我想要面向对象。有没有人有我的解决方案?我非常感谢一些帮助,但我正在寻找解决方案。如果你只是提出一个模糊的建议,我宁愿没有回应。编辑:这是我希望我的程序工作的方式:
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.ArrayList;
public class ShooterPanel extends JPanel
{
final int WIDTH = 200, HEIGHT = 100;
GoodGuy hero;
ArrayList<BadGuy> enemies = new ArrayList<BadGuy>();
ArrayList<Bullet> bullets = new ArrayList<Bullet>();
private Timer timer, bulletTimer;
final int DELAY = 200;
int count=0;
private boolean bulletOut = false;
public ShooterPanel()
{
hero = new GoodGuy(0, HEIGHT-20, 20);
addKeyListener(new MoveListener());
timer = new Timer(DELAY, new EnemyListener());
bulletTimer = new Timer(100, new BulletListener());
setPreferredSize(new Dimension (WIDTH, HEIGHT));
//enemies.add(new BadGuy(WIDTH-10, HEIGHT-10));
setFocusable(true );
timer.start();
}
public void paintComponent(Graphics page)
{
super.paintComponent(page);
hero.draw(page);
for (int i = 0; i < enemies.size(); i++)
{
enemies.get(i).draw(page);
}
if (bulletOut)
for(Bullet bullet: bullets)
bullet.draw(page);
}
private class MoveListener implements KeyListener
{
//--------------------------------------------------------------
//Responds to the user pressing arrow keys by adjusting the
//image and image location accordingly.
//--------------------------------------------------------------
public void keyPressed (KeyEvent event)
{
switch (event.getKeyCode())
{
case KeyEvent.VK_SPACE:
bullets.add(new Bullet(20,95));
bulletOut = true;
bulletTimer.start();
break;
}
}
//--------------------------------------------------------------
//Provide empty definitions for unused event methods.
//--------------------------------------------------------------
public void keyTyped (KeyEvent event) {}
public void keyReleased (KeyEvent event) {}
}
//*****************************************************************
// Represents the action listener for the timer.
//*****************************************************************
private class EnemyListener implements ActionListener
{
//--------------------------------------------------------------
// Updates the position of the image and possibly the direction
// of movement whenever the timer fires an action event.
//--------------------------------------------------------------
public void actionPerformed (ActionEvent event)
{
if (count%20==0)
enemies.add(new BadGuy(WIDTH-10, HEIGHT-10));
for (BadGuy enemy: enemies)
{
enemy.move();
}
count++;
repaint();
}
}
private class BulletListener implements ActionListener
{
//--------------------------------------------------------------
// Updates the position of the image and possibly the direction
// of movement whenever the timer fires an action event.
//--------------------------------------------------------------
public void actionPerformed (ActionEvent event)
{
for(Bullet bullet: bullets)
bullet.move();
for(int i = 0; i < bullets.size(); i++)
{
if (enemies.size() != 0)
{
if (bullets.get(i).getX() > enemies.get(0).getX())
{
bullets.remove(i);
enemies.remove(0);
}
}
if (bullets.size() != 0)
{
if (bullets.get(i).getX()>WIDTH)
bullets.remove(i);
}
}
repaint();
}
}
}
import java.awt.*;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
public class GoodGuy
{
private int x, y, size;
private Bullet bullet;
public GoodGuy(int x, int y, int height)
{
size = height;
this.x = x;
this.y = y;
}
public int getSize()
{
return size;
}
public void draw(Graphics page)
{
page.drawRect(x, y, size, size);
}
public void shoot()
{
bullet = new Bullet(x+size, y);
}
}
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class BadGuy
{
private int x, y;
final int RADIUS = 5;
public BadGuy(int x, int y)
{
this.x = x;
this.y = y;
}
public void move()
{
x -= 5;
}
public void draw(Graphics page)
{
page.drawOval(x, y, RADIUS*2, RADIUS*2);
}
public int getX()
{
return x;
}
}
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.Timer;
public class Bullet
{
private int x, y;
final int LENGTH = 5, DELAY =200;
public Bullet(int x, int y)
{
this.x = x;
this.y = y;
}
public void draw(Graphics page)
{
page.drawLine (x, y, x+LENGTH, y);
}
public void move()
{
x += 5;
}
public int getX()
{
return x;
}
}
射手类保持不变。这就是我希望程序要做的事情,但这并不是我想要它做到的。我更喜欢它是否更加面向对象,每个类都照顾好自己。 ShooterPanel已经开始对我的品味有点复杂,并且随着更多的添加到程序中而变得更糟。我想改变的一件事是每个子弹都有自己的计时器,在Bullet类中定义了一个ActionListener。但是,我无法弄清楚如何以每次计时器触发事件时重新绘制子弹的方式执行此操作。如果有人知道这样做的方法,请告诉我。
答案 0 :(得分:0)
你需要让你的ShooterPanel成为焦点。添加:
setFocusable(true);
requestFocusInWindow();
从不设置BulletListener的图形。这种绘画应该可能发生在ShooterPanel本身。
答案 1 :(得分:0)
尝试利用KeyBindings API代替KeyListener
,如果设置正确,则应该重点关注问题。