import java.awt.Color; import java.awt.Frame; import java.awt.Graphics; import java.awt.Point; import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import java.awt.event.MouseListener; import java.util.ArrayList; import java.util.Iterator; public class MyMouseAdapter { public static void main(String[] args) { new MyFrame5("drawing"); } } class MyFrame5 extends Frame{ ArrayList points=null; MyFrame5(String s){ super(s); points=new ArrayList(); setLayout(null); setBounds(300,300,400,300); this.setBackground(new Color(204,204,255)); setVisible(true); this.addMouseListener(new Monitor5()); } public void paint(Graphics g){ Iterator i=points.iterator(); while(i.hasNext()){ Point p=(Point)i.next(); g.setColor(Color.blue); g.fillOval(p.x,p.y, 10, 10); } } public void addPoint(Point p){ points.add(p); } } class Monitor5 extends MouseAdapter{ //MouseAdapter实现了MouseListener接口 public void mousePressed(MouseEvent e){ MyFrame5 f=(MyFrame5)e.getSource(); f.addPoint(new Point(e.getX(),e.getY())); f.repaint(); //让Frame强制经行重画 } } |