nationday.java

一个用JAVA编写的字幕的滚动 很精致

package java1;
import java.awt.*;
import java.applet.*;
import java.awt.image.*;
import java.io.*;
public class NationDay extends Applet implements Runnable
{ 
  MediaTracker tracker =null;
  int frame_x=0;
  boolean bz_load=false;
  boolean bz_anima=false;
  int current=0;
  private boolean init=false;
  private AudioClip m_Audio;
  Image backImage=null;
  Image myImage=null;
  Image allImages[]=null;
  Thread animation=null;
  public void init() 
  {
     if(init==false){
         init=true;
         tracker=new MediaTracker(this);
         allImages=new Image[7];
         for(int x=0;x<7;x++)
             allImages[x]=getImage(getCodeBase(),"Mrab0"+x+".gif");
         for(int x=0;x<7;x++)
             tracker.addImage(allImages[x],x);
            backImage=getImage(getCodeBase(),"50.gif");
            
     }
    }
   public void main(Graphics g)//开始动画
   {
       setBackground(Color.white);
       if(bz_load){
           bz_anima=true;
           g.drawImage(backImage,0,0,this);
           g.drawImage(allImages[current],frame_x,0,this);
       }
       else
       {
           g.drawString("画面载入中，请稍候……",0,20);
           
       }
   }
   public void start()
   { String strAudio="spacemusic.au";
     m_Audio=getAudioClip(getDocumentBase(),strAudio);
     if( m_Audio!=null)
          m_Audio.loop();
        if(animation==null){
            animation=new Thread (this);
            animation.start();
        }
}
   public void stop()
   {
      if(m_Audio!=null)
         m_Audio.stop();
      if(animation!=null){
          animation.stop();
           animation=null;
      }
   }
   public void run()
   {
       while(!checkRoll())sleep(100);
       bz_load=true;
       while(true){
           roll(0,this.getSize().width-42);
           
       }
   }
   boolean checkRoll()
   {  boolean finished=true;
      for(int i=0;i<7;i++){
          if((tracker.statusID(i,true)& MediaTracker.COMPLETE)==0)
              finished=false;
      }
      return finished;
   }
   void roll(int begin,int end)//播放动画
   { if(begin<end){
         for(int x=begin;x<=end;x+=21){
             frame_x=x;
             repaint();
             current--;
             if(current==-1)current=3;
             sleep(150);
             
         }
     }
     else{
         for(int x=begin;x<=end;x-=21){
             frame_x=x;
             repaint();
             current++;
             if(current==7)current=0;
             sleep(150);
             
         }
     }
   }
   private void sleep(int a)
   { 
       try{ 
            Thread.sleep(a);
       }
       catch (InterruptedException e){
       }
       
       }
   public void update(Graphics g)//刷新
   {  g.clipRect(0,0,2000,2000);
      paint(g);
   }
   }