为什么我的Java Applet闪烁？

Question

我正在研究一个小的Java Applet，它在屏幕上有3个球反弹。 当它们与墙壁碰撞时，它们发出一种声音，而当彼此碰撞时，它们发出另一种声音。

我的问题是球由于某种原因而闪烁，我不确定为什么。 如果有人可以解释为什么他们在忽悠，我将如何解决该问题，将不胜感激。

这是我的代码：

import java.applet.*;
import java.awt.*;
import java.awt.event.*;

public class ass3 extends Applet implements Runnable {
int[] positionX = {0, 0, 0};
int[] positionY = {0, 0, 0};
int[] incrementX = {3, 7, 4};
int[] incrementY = {8, 4, 5};
Thread t;
AudioClip sound;
AudioClip collide;
public void init(){
    sound = getAudioClip(getDocumentBase(), "Audio1.au");
    collide = getAudioClip(getDocumentBase(), "Audio2.au");
}
public void start() {
    t = new Thread(this);
    t.start();
}
public void paint(Graphics g) {
    g.fillOval(getWidth()-50-positionX[0], getHeight()-50-positionY[0], 50, 50);
    g.fillOval(getWidth()-450-positionX[1], getHeight()-450-positionY[1], 50, 50);
    g.fillOval(getWidth()-450-positionX[2], getHeight()-50-positionY[2], 50, 50);
}
public void run() {
    while (true) {
        try {
        Thread.sleep(30);
        } catch (InterruptedException e) {}
        for (int i=0; i < 3; i++) {
            positionX[i] += incrementX[i];
            positionY[i] += incrementY[i];
        }
        // ball 1
        if (positionX[0] > 500 || positionX[0] < 0) {
            incrementX[0] = -incrementX[0];
            sound.play();
        }
        repaint();
        if (positionY[0] > 500 || positionY[0] < 0) {
            incrementY[0] = -incrementY[0];
            sound.play();
        }
        repaint();
        // ball 2
        if (positionX[1] > 100 || positionX[1] < -400) {
            incrementX[1] = -incrementX[1];
            sound.play();
        }
        repaint();
        if (positionY[1] > 100 || positionY[1] < -400) {
            incrementY[1] = -incrementY[1];
            sound.play();
        }
        repaint();
        // ball 3
        if (positionX[2] > 100 || positionX[2] < -400) {
            incrementX[2] = -incrementX[2];
            sound.play();
        }
        repaint();
        if (positionY[2] > 500 || positionY[2] < 0) {
            incrementY[2] = -incrementY[2];
            sound.play();
        }
        repaint();
        // collision
        if (Math.sqrt(((getWidth()-50-positionX[0])-(getWidth()-450-positionX[1]))*((getWidth()-50-positionX[0])-(getWidth()-450-positionX[1])) + ((getHeight()-50-positionY[0])-(getHeight()-450-positionY[1]))*((getHeight()-50-positionY[0])-(getHeight()-450-positionY[1]))) <= 50) {
            incrementX[0] = -incrementX[0];
            incrementY[0] = -incrementY[0];
            incrementX[1] = -incrementX[1];
            incrementY[1] = -incrementY[1];
            collide.play();
        }
        repaint();
        if (Math.sqrt(((getWidth()-50-positionX[0])-(getWidth()-450-positionX[2]))*((getWidth()-50-positionX[0])-(getWidth()-450-positionX[2])) + ((getHeight()-50-positionY[0])-(getHeight()-50-positionY[2]))*((getHeight()-50-positionY[0])-(getHeight()-50-positionY[2]))) <= 50) {
            incrementX[0] = -incrementX[0];
            incrementY[0] = -incrementY[0];
            incrementX[2] = -incrementX[2];
            incrementY[2] = -incrementY[2];
            collide.play();
        }
        repaint();
        if (Math.sqrt(((getWidth()-450-positionX[2])-(getWidth()-450-positionX[1]))*((getWidth()-450-positionX[2])-(getWidth()-450-positionX[1])) + ((getHeight()-50-positionY[2])-(getHeight()-450-positionY[1]))*((getHeight()-50-positionY[2])-(getHeight()-450-positionY[1]))) <= 50) {
            incrementX[2] = -incrementX[2];
            incrementY[2] = -incrementY[2];
            incrementX[1] = -incrementX[1];
            incrementY[1] = -incrementY[1];
            collide.play();
        }
        repaint();
    }
}

}

Answer 1

很简单，停止多次调用重绘。 （您在while循环中多次调用它）。