HelloWindow Java图形案例1

效果：

package CH03;

import java.awt.event.*;
import java.awt.*;

class HelloWindow implements ActionListener
{
 private Frame f=new Frame("Hello");
  private Button btn=new Button("OK");
  private Label l=new Label("Hello World");
 
  public static void main(String[] args)
  {
   HelloWindow hw=new HelloWindow();
    hw.init();
 }
       
  private void init()
  {
    f.add("Center",l);
    f.add("North",btn);              
    btn.addActionListener(this);
   f.setVisible(true);
    f.setSize(320,150);
    f.setResizable(true);
    f.setLocation(300,200);
  }
       
  public void actionPerformed(ActionEvent e)
  {
    f.setVisible(false);
    System.exit(0);
  }
}