java - 元件尺寸问题!由于我不知道的原因调整为 parent 的尺寸!

Question

我似乎无法弄清楚为什么会发生这种情况......

我的 serverPaddle(它基于 java.awt.Component)的大小不正确。我已经放置了 System.out.println(serverPaddle.getSize());在线程循环中，它显示该组件的大小适合 1 个循环，然后是下一个循环，其后的大小与父级(容器)相同。

import javax.swing.JFrame;
import java.awt.Container;
import java.awt.Color;
import java.awt.Graphics;

    private final int FRAMERATE = 60,       THIS_MUCH = 1000/FRAMERATE,
        BALL_DIAMETER = 30,                               BALL_SPEED = 15,    
        PADDLE_WIDTH = 15,    PADDLE_HEIGHT = 60,         PADDLE_SPEED = 30;
    private final Color BALL_COLOR = Color.WHITE, PADDLE_COLOR = Color.WHITE;

    private Container c;
    private Ball puck;
    private Paddle serverPaddle, clientPaddle;

...

    private Container c;

...

    c = getContentPane();

...

    public void run() {

        //Center puck
        puck = new Ball(c.getWidth()/2 - BALL_DIAMETER/2,
                        c.getHeight()/2 - BALL_DIAMETER/2, BALL_SPEED);
        puck.setSize(BALL_DIAMETER, BALL_DIAMETER);
        puck.setForeground(BALL_COLOR);
        puck.createHitbox();
        puck.setMoving(true);

        //West paddle
        serverPaddle = new Paddle(PADDLE_WIDTH,
                            c.getHeight()/2 - PADDLE_HEIGHT/2,
                            PADDLE_SPEED);
        serverPaddle.setSize(PADDLE_WIDTH, PADDLE_HEIGHT);
        serverPaddle.setForeground(PADDLE_COLOR);
        serverPaddle.createHitbox();

        c.add(puck);
        c.add(serverPaddle);

        //Draw at FRAMERATE frames per second
        while (true) {
            System.out.println(serverPaddle.getSize());
            puck.move(determineSituation());
            puck.repaint();
            wait(THIS_MUCH);
        }
    }

这是 Paddle 类

import java.awt.Graphics;
import java.awt.Color;
import java.awt.event.KeyListener;
import java.awt.event.KeyEvent;

public class Paddle extends GameObject implements KeyListener {

    private int x = 0, y = 0;

    public Paddle(int x, int y, int speed) {
        super(speed);
        this.x = x;
        this.y = y;
    }

    public void keyTyped(KeyEvent e) {
    }

    public void keyPressed(KeyEvent e) {
    }

    public void keyReleased(KeyEvent e) {
    }

    public void paint(Graphics g) {
        setLocation(x, y);

        //These two are the culprits, the size is correct when
        //I use constants instead.
        g.fillRect(0, 0, **getWidth()**, **getHeight()**);
        updateHitbox();
    }
}

我的 GameObject 类...

import java.awt.Component;
import java.awt.Rectangle;

public class GameObject extends Component {

    /* Members */
    private int speed = 0;
    private boolean isMoving = false;
    private Rectangle hitbox;

    //Dead south = 0 radians, anti-clockwise
    private double direction = 0;

    public GameObject(int speed) {
        this.speed = speed;
    }

    /* Accessors */
    public boolean isMoving() { return isMoving; }
    public void setMoving(boolean isMoving) { this.isMoving = isMoving; }

    public int getSpeed() { return speed; }
    public void setSpeed(int speed) { this.speed = speed; }

    public double getDirection() { return direction; }
    public void setDirection(double direction) { this.direction = direction; }

    public Rectangle getHitbox() { return hitbox; }
    public void createHitbox() { 
        hitbox = new Rectangle(getX(), getY(), getWidth(), getHeight());
    }

    public void createHitbox(int x, int y, int width, int height) { 
        hitbox = new Rectangle(x, y, width, height);
    }

    public void updateHitbox() {
        hitbox.setLocation(getX(), getY());
    }
}

即使我注释掉球/冰球的所有代码，它也不起作用。注释掉“wait”方法也不起作用。它只是由于某种我不知道的原因而发生了变化，但我真的很想知道，这样我就可以修复这个问题!!11

救命啊!谢谢。

顺便说一句，wait只是调用Thread.sleep

public void wait(int durationInMilliseconds) {
    try {
        Thread.sleep(durationInMilliseconds);
    } catch (InterruptedException e) {
        System.out.println(e);
    }
}

Answer 1

首先，代码量非常大。您希望能够将问题缩小到足够小，使其变得微不足道。如果您希望其他人提供帮助，那么通常最好能够生成一个完整的、可编译的程序来显示问题而不是其他内容。

事实上，您似乎正在使用带有默认 LayoutManager 的 JFrame 内容 Pane 。这将默认为 BorderLayout。当您添加组件而不指定约束时，它们将被添加到“中心”。如果没有任何侧面组件，中心组件将展开以填充所有可用区域。

所以设置一个合适的布局管理器。我更喜欢创建 JPanel 并使用 setContentPane，而不是必须围绕 getContentPane 改变我的代码结构。