问绘制具有随机设置的同心圆系列

EN

// Exercise 12.6 Solution: CirclesJPanel.java
// This program draws concentric circles
import java.awt.Graphics;
import javax.swing.JPanel;

public class ConcentricCircles extends JPanel
{
  // draw eight Circles separated by 10 pixels
   public void paintComponent( Graphics g )
   {
      Random random = new Random();
      super.paintComponent( g );

      // create 8 concentric circles
      for ( int topLeft = 0; topLeft < 80; topLeft += 10 )
      {
         int radius = 160 - ( topLeft * 2 );
         int r = random.nextInt(255);
         int gr = random.nextInt(255);
         int b = random.nextInt(255);
         Color c = new Color(r,gr,b);
         g.setColor(c);
         g.drawArc( topLeft + 10, topLeft + 25, radius, radius, 0, 360 );
      } // end for
   }  
}

// This program draws concentric circles
import javax.swing.JFrame;

public class ConcentricCirclesTest extends JFrame {
    /**
    * @param args
    */
    public static void main(String[] args) {
        // TODO Auto-generated method stub

        JFrame frame=new JFrame("Concentric Circles");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        ConcentricCircles cCirclesJPanel = new ConcentricCircles();
        frame.add(cCirclesJPanel);
        frame.setSize(200,250);
        frame.setVisible(true);


    }//end main
}