Java 具有随机颜色的弹跳球应用程序

Question

我被交给了在我成功创建的程序中使球弹跳的任务。现在，我尝试专注于更高级的功能，例如第二个球(我已经成功完成)，并使球每次弹跳时都变为随机颜色。

我对 Java 和一般编码都很陌生，但我已经成功地做到了，当它们第一次撞到墙上时，它们都会变成随机颜色。但是，我似乎无法让它每次弹跳时都变成不同的颜色。有人对如何实现这一目标有任何建议吗？

import java.awt.Color;
import java.awt.Graphics;
import java.util.Random;


public class MainClass extends javax.swing.JFrame implements Runnable {
int width ;
int height ;
int ball;
int ball2;
int posX;
int posY;
int posX2;
int posY2;
int dx = 8;
int dy = 8;//dx dy are varuiables for the movement of the ball
int dx2 = -8;
int dy2 = -8;
Random rand = new Random();
float r = rand.nextFloat();
float g = rand.nextFloat();
float b = rand.nextFloat();
float r2 = rand.nextFloat();
float g2 = rand.nextFloat();
float b2 = rand.nextFloat();
Color randomColor = new Color(r, g, b);
Color randomColor2 = new Color(r2,g2,b2);
Color c1 = Color.BLUE;
Color c2 = Color.GREEN;
Thread move = new Thread (this);


public void paint(Graphics g) {
    g.setColor(Color.BLACK);
    g.fillRect(0,0,width,height);
    g.setColor(c1);
    g.fillOval(posX ,posY ,ball,ball); 
    g.setColor(c2);
    g.fillOval(posX2,posY2, ball2,ball2);

    // sets starting position of Oval(ball)
  }

  public void run(){
  try {
        while (true){
          posX=posX+dx;
          posY=posY+dy;
          posX2=posX2+dx2;
          posY2=posY2+dy2;
          //this is the speed of the ball
          repaint();

          move.sleep(100);


          //This shows the ball on the screen
                if (posY > height - ball)
                {
                    dy = dy *-1;
                    c1 = randomColor;
                  }
                if ( posY <0 - ball)
                {
                    dy = dy *-1;
                    c1 = randomColor;
                  }
                if(posX > width - ball)
                {
                    c1 = randomColor;
                    dx = dx*-1; 
                }
                if(posX <0 - ball )
                {
                    c1 = randomColor;
                    dx = dx*-1; 
                }
                // This code is for the first ball
                if(posX > width - ball2 || posX <0 - ball2)
                {
                    dx2 = dx2*-1;
                    c2 = randomColor2;
                }
                if(posY > height - ball2 || posY <0 - ball2)
                {
                    dy2 = dy2 *-1;
                    c2 = randomColor2;
                }
      }
    }
  catch(Exception ex) {
      ex.printStackTrace();

  }
}

public MainClass() {
    initComponents();
    this.setResizable(false);
    width = getWidth();
    height = getHeight();
    //this code creates the program dimensions
    posX = width/2;
    posY = height/2;
    posX2 = width/2;
    posY2 = height/2;
    ball = 20;
    ball2= 20;

Answer 1

每次设置后更改randomColor的颜色，这样下次设置时它就会不同。