flash.java

这个能闪烁的显示字符串的程序还是GUI初学者必看的.

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
 
public class Flash extends JFrame{
	 public Flash() {
          FlashLabel m= new FlashLabel("Welcome to pudn!!!");
		 this.getContentPane().add(m);
		}
		
		/*main method*/
	public static void main(String[] args){ 
		JFrame frame1 = new Flash();
         frame1.setTitle("Flash");
		 frame1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		 frame1.setSize(300,200);
		 frame1.setVisible(true);
		  
		 }
	 
	class FlashLabel extends JPanel implements ActionListener {
    private boolean visible = true;
    private Timer timer = new Timer(100, this); 
    
    String label = " ";
    
    public FlashLabel(String label) {
      this.label = label;
      timer.start();
    }
    
    public void setLabel(String label) {
      this.label = label;
    }
    
    public void actionPerformed(ActionEvent e) { 
      repaint();
    }
    
    public void paintComponent(Graphics g) {
      super.paintComponent(g);
      
      if (visible)
        g.drawString(label, 30, 30);
      visible = !visible; 
    }
    
    public Dimension getPreferredSize() {
      return new Dimension(200, 50);
    }
  }	
  }