编辑：抱歉，伙计们，但另一个话题没有帮助。看：它只是一个副本+粘贴。只有那个。
原始代码是：
p.update();
Blinky.update();
maze.update();
dc.eatDot(p);
pc.eatPill(p);
gc.collision(p);
gc.collision(Blinky);
现在是：
p.update();
Blinky.update();
Pinky.update();
Inky.update();
Clyde.update();
maze.update();
dc.eatDot(p);
pc.eatPill(p);
gc.collision(p);
gc.collision(Blinky);
gc.collision(Pinky);
gc.collision(Inky);
gc.collision(Clyde);
在构造函数上：
Blinky = new Ghost(240, 250, 0);
Pinky = new Ghost(105, 69, 1);
Inky = new Ghost(465, 573, 2);
Clyde = new Ghost(321, 357, 3);
幽灵班：
package objects;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Rectangle;
import java.io.IOException;
import java.util.Random;
public class Ghost extends Entity {
private int lastDir = 0;
public int rndDir;
public int tipo;
private int chase = 0;
//private int state; //0 - scatter, 1 - chase, 2 - frightened
public Ghost(int x, int y, int tipo){
this.x = x;
this.y = y;
this.tipo = tipo;
init();
}
@Override
public void init(){
//state = 0;
this.startFrame = 4;
this.endFrame = startFrame + 1;
this.frameNumber = startFrame;
this.frameSpeed = 4; //quanto maior, mais lento
try{
if(this.tipo == 0){
this.ss = new SpriteSheet(i.load("/img/gBlinky.png"));
System.out.println("Criado Blinky!");
} else if(this.tipo == 1){
this.ss = new SpriteSheet(i.load("/img/gPinky.png"));
System.out.println("Criado Pinky!");
}else if(this.tipo == 2){
this.ss = new SpriteSheet(i.load("/img/gInky.png"));
System.out.println("Criado Inky!");
}else if(this.tipo == 3){
this.ss = new SpriteSheet(i.load("/img/gClyde.png"));
System.out.println("Criado Clyde!");
}
}catch (Exception e){System.out.println("Erro na inicialização dos fantasmas: "+e);}
this.velX = -speed;
//preVelX = -speed;
}
@Override
public void update(){
try{
this.x += velX;
this.y += velY;
//passagem pelo túnel
if(this.x < -35 && y > 290 && this.y < 310)
this.x = 494;
if(this.x > 510 && y > 290 && this.y < 310)
this.x = -19;
this.Animation();
} catch(NullPointerException s) {
//s.printStackTrace();
throw new IllegalStateException("Some Ghost has a null property", s);
}
}
public void chase(Entity e){
Random rndGen = new Random();
chase = rndGen.nextInt(1000);
if(chase % 2 == 0){
if(e.x > this.x){
velX = speed;
} else {
velX = -speed;
}
preVelY = 0;
} else {
if(e.y > this.y){
velY = speed;
} else {
velY = -speed;
}
velX = 0;
}
}
@Override
public void collisionGate(Gate gate){
boolean[] g = new boolean[4];
g[0] = gate.up;
g[1] = gate.right;
g[2] = gate.down;
g[3] = gate.left;
if(velX != 0){
if(velX > 0)
g[3] = false;
else
g[1] = false;
}
if(velY != 0){
if(velY > 0)
g[0] = false;
else
g[2] = false;
}
int saidas = 0;
for(int i = 0; i < g.length; i++){
if(g[i] == true){
saidas++;
}
}
if((velX > 0 && gate.right == false) ||
(velX < 0 && gate.left == false) ||
(velY > 0 && gate.down == false) ||
(velY < 0 && gate.up == false) ||
saidas > 1){
Random rndGen = new Random();
do{
rndDir = rndGen.nextInt(4);
} while(g[rndDir] == false);
setVel(rndDir);
}
}
public void setVel(int k){
switch(k){
default: System.out.println("Erro em setVel()");
break;
case 0:
velY = -speed;
velX = 0;
break;
case 1:
velX = speed;
velY = 0;
break;
case 2:
velY = speed;
velX = 0;
break;
case 3:
velX = -speed;
velY = 0;
break;
}
changeDirection();
}
@Override
public void draw(Graphics g){
g.drawImage(getEntityImage(), x, y, null);
}
public void changeDirection(){
if(velX > 0){
startFrame = 0;
endFrame = startFrame + 1;
frameNumber = startFrame;
}
if(velX < 0){
startFrame = 4;
endFrame = startFrame + 1;
frameNumber = startFrame;
}
if(velY > 0){
startFrame = 2;
endFrame = startFrame + 1;
frameNumber = startFrame;
}
if(velY < 0){
startFrame = 6;
endFrame = startFrame + 1;
frameNumber = startFrame;
}
}
}
实体抽象类：
package objects;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Rectangle;
public abstract class Entity {
public ImageLoader i = new ImageLoader();
public SpriteSheet ss;
public int frame;
public int frameSpeed, frameNumber, startFrame, endFrame;
public int counterSS = 0;
public Image frameSS;
public int centerX, centerY;
public int x,y;
public int velX, velY;
public int preVelX, preVelY;
public int speed = 3;
public void init(){}
public void update(){}
public void draw(Graphics g){}
public void collisionGate(Gate gate){}
public Image getEntityImage(){
return frameSS;
}
public void Animation(){
frameSS = ss.crop2(25*frameNumber, 0, 25, 25);
//System.out.println(counterSS);
if(counterSS % frameSpeed == 0){
if(frameNumber < endFrame){
frameNumber++;
} else {
frameNumber = startFrame;
}
}
if(counterSS > 20*frameSpeed){
counterSS = 0;
}else {
counterSS++;
}
if(velX == 0 && velY == 0)
counterSS--;
}
public Rectangle getBounds(){
Rectangle r = new Rectangle(this.x, this.y, 25, 25);
return r;
}
public Rectangle getCenterBounds(){
Rectangle r = new Rectangle(this.x+11, this.y+11, 3, 3);
return r;
}
}
我正在做PacMan学习。它与一个鬼完美配合，但当我尝试创建多个鬼时，我收到以下错误：
Criado Blinky!
Criado Pinky!
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
Criado Inky!
Criado Clyde!
at pacman.GamePanel.actionPerformed(GamePanel.java:113)
at javax.swing.Timer.fireActionPerformed(Timer.java:312)
at javax.swing.Timer$DoPostEvent.run(Timer.java:244)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:705)
at java.awt.EventQueue.access$000(EventQueue.java:101)
at java.awt.EventQueue$3.run(EventQueue.java:666)
at java.awt.EventQueue$3.run(EventQueue.java:664)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:675)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:211)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:117)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:90)
您可以在以下位置查看完整代码： https://github.com/dimarcinho/pacman
当我运行Debug时，它也会给我一个非常奇怪的消息：
Ouvindo em javadebug Executando programadousuárioNãofoipostívelenviaro pontodeinterruptçãoShapeBreakpoint[objects.Ghost] .collisionGate2'（Lobjects / Gate;）Lvoid;'，razão：Ométodo'trackzeGate2'comassinatura'（Lobjects /栅极;）Lvoid;” nãoreistena classe objects.Ghost。
英文：
听javadebug; 运行用户程序
无法发送中断点MethodBreakpoint [objects.Ghost] .collisionGate2'（Lobjects / Gate;）Lvoid;'，原因： 方法'collisionGate2'与签名'（Lobjects / Gate;）Lvoid;' 类对象上不存在.Ghost。
我正在尝试使用某些代码来运行collisionGate（）方法，这是其中一项试验，但我已将其删除，并且不会在任何地方使用它！对我来说很奇怪！方法collisionGate2不再存在！
同样奇怪的是，如果我试着和两个鬼一起跑，有时它会起作用，有时候不行！ ：$
答案 0 :(得分：0)
好的，伙计们！我发现了问题。
在构造函数中，我有：
public GamePanel(){
setFocusable(true);
t = new Timer(20, this);
t.start();
maze = new Maze();
dc = new DotController();
gc = new GateController();
pc = new PillController();
maze.createDots(dc);
maze.createPills(pc);
maze.createGates(gc);
p = new Player(240, 465);
Blinky = new Ghost(240, 250, 0);//240,250
Pinky = new Ghost(105, 69, 1);
Inky = new Ghost(465, 573, 2);
Clyde = new Ghost(321, 357, 3);
addKeyListener(new KeyInput(p));
init();
}
我刚刚将Timer的实例更改为结束，现在它正在运行。我认为毫秒的差异导致了错误。它也解释了为什么有时它会与两个幽灵合作，有时候没有。
感谢您的帮助！
最终代码：
public GamePanel(){
setFocusable(true);
maze = new Maze();
dc = new DotController();
gc = new GateController();
pc = new PillController();
maze.createDots(dc);
maze.createPills(pc);
maze.createGates(gc);
p = new Player(240, 465);
Blinky = new Ghost(240, 250, 0);//240,250
Pinky = new Ghost(105, 69, 1);
Inky = new Ghost(465, 573, 2);
Clyde = new Ghost(321, 357, 3);
addKeyListener(new KeyInput(p));
init();
t = new Timer(20, this);
t.start();
}