flyingwords.java

来自「Java案例开发集锦,里面提供了很好的学习例子」· Java 代码 · 共 69 行

import java.awt.*;
import java.applet.*;

public class FlyingWords extends Applet implements Runnable{
   
   private Image myImage;
   private Graphics myGraphic;
   private Font font;
   private String myString;
   private Thread mythread;
   private int fontSize;
   
   public void init(){
   
      String myText;
      myImage = createImage(getSize().width, getSize().height);   
      myGraphic = myImage.getGraphics();
      myText = getParameter("text");
      if(myText == null)
         myString = "你好！";
      else
         myString = myText;
      
      font = new Font("TimesRoman", Font.BOLD, 10);
      
   }
   public void start(){
      if(mythread == null){
         mythread =  new Thread(this);
         mythread.start();
      }
   }
   
   public void update(Graphics g){
      paint(g);
   }
   public void paint(Graphics g){
      myGraphic.setColor(Color.blue);
      myGraphic.fillRect(0,0,getSize().width, getSize().height);
   
      font = new Font("TimesRoman", Font.BOLD, fontSize);
      myGraphic.setFont(font);
      myGraphic.setColor(Color.red);
      FontMetrics fm = myGraphic.getFontMetrics(font);
      int fontHeight = fm.getHeight();
      int w;
      int baseLine = getSize().height / 2 + fontHeight / 2;      
      
      w = fm.stringWidth(myString);      
      w = (getSize().width - w) / 2;
      
      myGraphic.drawString(myString, w, baseLine-=20);   
      g.drawImage(myImage,0,0, this);
      fontSize++;
      

   }
   
   public void run(){
      while(true){
         repaint();
         if(fontSize >getSize().height)
            fontSize = 0;
         try{
            mythread.sleep(50);
         }catch (InterruptedException e){}
      }      
   }
}