// app18_1, 簡單的繪圖
import java.awt.*;  
import java.awt.event.*;
public class app18_1 extends Frame implements ActionListener
{
   static app18_1 frm=new app18_1();
   static Button btn=new Button("Draw");
   
   public static void main(String args[])
   {
      BorderLayout br=new BorderLayout();
      frm.setTitle("Drawing example");
      frm.setLayout(br);
      frm.setSize(200,150);
      frm.add(btn,br.SOUTH);
      btn.addActionListener(frm);
      frm.show();
   }
   public void actionPerformed(ActionEvent e)
   {
      Graphics g=getGraphics();  // 取得窗口的繪圖區
      g.drawRect(100,50,70,55);  // 繪出長方形
   }
}