我拥有代表简单游戏中的每个对象(玩家,敌人,射线等等)的类 - 它们都有许多共同点,如速度,位置,dmg)。所以我做了一个叫Thing的课。下面是它的样子:抽象类中的私有字段不能在子类中访问
public abstract class Thing {
private Image image;
private float x;
private float y;
private float speed;
private final int WIDTH;
private final int HEIGHT;
public Thing(String filename, float x, float y, float speed) {
try {
Image image = ImageIO.read(new File(filename));
} catch (Exception e) {}
this.x = x;
this.y = y;
this.speed = speed;
WIDTH = image.getWidth(null);
HEIGHT = image.getHeight(null);
}
//Zwraca ksztalt do sprawdzania czy contains...
public Rectangle2D getShade() {
return new Rectangle2D.Float(x, y, WIDTH, HEIGHT);
}
public Image getImage() {
return image;
}
public Point2D getPoint() {
return new Point2D.Float(x, y);
}
public float getX() {
return x;
}
public float getY() {
return y;
}
}
我已扩展的类球员:
public class Player extends Thing {
public Player(String filename, float x, float y, float speed) {
super(filename, x, y, speed);
}
public void moveToPoint(Point2D targetPoint) {
int targetX = (int)targetPoint.getX();
int targetY = (int)targetPoint.getY();
if (((int)x+20 < targetX+3) && ((int)x+20 > targetX-3)) {
return;
}
float distanceX = targetX - x;
float distanceY = targetY - y;
//Dodanie 20px wymiarow statku
distanceX -= 20;
distanceY -= 20;
//Ustalenie wartosci shiftow
float shiftX = speed;
float shiftY = speed;
if (abs(distanceX) > abs(distanceY)) {
shiftY = abs(distanceY)/abs(distanceX) * speed;
}
if (abs(distanceY) > abs(distanceX)) {
shiftX = abs(distanceX)/abs(distanceY) * speed;
}
//Zmiana kierunku shifta w zaleznosci od polozenia
if (distanceX < 0) {
shiftX = -shiftX;
}
if (distanceY < 0) {
shiftY = -shiftY;
}
//Jezeli statek mialby wyjsc poza granice to przerywamy
if ((((int)x+shiftX < 0) || ((int)x+shiftX > 260)) || ((y+shiftY < 0) || (y+shiftY > 360))) {
return;
}
//Zmiana pozycji gracza
x += shiftX;
y += shiftY;
}
}
这里是问题,因为我的IDE强调x,y和速度场红色,并告诉他们不能被访问来自Player类。我试图将它们更改为私有和默认,但之后出现错误。我究竟做错了什么?当我从扩展Thing的类创建新的对象时,我想复制所有的字段,并像在构造函数中那样初始化它们。那么如何修复它?
“问题”这个词不是没有理由在标题中被禁止的。如果每个人都把他的问题称为“Java问题”,那么只要看看标题,人们就会知道它是什么问题?尝试在标题中描述具体问题本身,而不是使用“问题”这个词:) :) – BalusC