java - 在java中绘制多个椭圆

Question

我目前正计划编写一些用于碰撞检测的代码。但是，我遇到了一个问题。我想在 JFrame 窗口上绘制多个球体，但以下代码不起作用...请帮助我...这是我的代码:-

    import javax.swing.*;
    import java.awt.*;
    class Draw extends JPanel
    {
        public void paintComponent(Graphics g)
        {
            super.paintComponent(g);
            for(int i=0;i<20;i++)
                drawing(g,new Sphere());
        }
        public void drawing(Graphics g,Sphere s)
        {
            g.setColor(s.color);
            g.fillOval(s.x,s.y,s.radius*2,s.radius*2);
        }
        public static void main(String args[])
        {
            JFrame jf = new JFrame("Renderer");
            jf.getContentPane().add(new Draw(),BorderLayout.CENTER);
            jf.setBounds(100,100,400,300);
            jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            jf.setVisible(true);
        }
    }
    class Sphere
    {
        int x;
        int y;
        int radius;
        Color color;
        public Sphere()
        {
            this.x = (int)Math.random()*100;
            this.y = (int)Math.random()*100;
            this.radius = (int)Math.random()*20;
            this.color = new Color((int)(Math.random()*255),
    (int)(Math.random()*255),(int)(Math.random()*255));
        }
    }

Answer 1

将随机值转换为 int，使其为 0，然后将其相乘。你的球体构造函数应该看起来像

public Sphere() {
        this.x = (int) (Math.random() * 100); // cast the result to int not the random
        this.y = (int) (Math.random() * 100);
        this.radius = (int) (Math.random() * 20);
        this.color = new Color((int) ((Math.random() * 255)), (int) (Math.random() * 255), (int) (Math.random() * 255));
}