import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Ball extends JPanel implements Runnable
{
/**
*
*/
JFrame frame ;
int x = 30 ;
private static final long serialVersionUID = 1L ;
public Ball ()
{
frame = new JFrame () ;
frame.add(this) ;
frame.setSize(500,500) ;
frame.setVisible(true) ;
}
public void paintComponent(Graphics g)
{
super.paintComponents(g) ;
g.setColor(new Color (238,238,238)) ;
g.fillOval(x-3,30,100,100) ;
g.setColor(Color.RED) ;
g.fillOval(x,30,100,100) ;
}
@Override
public void run()
{
while(true)
{
this.x = this.x + 3 ;
try
{
Thread.sleep(70) ;
repaint () ;
}
catch (InterruptedException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
public static void main (String [] args)
{
Thread th = new Thread (new Ball ()) ;
th.start() ;
}
}
只要添加包名就可以运行了。我想问的是
Thread th = new Thread (new Ball ()) ; 为什么要new一个ball然后传入Thread里面呢?
为什么要这样做呢?为了可以使用run方法吗?