simplebanner.java

JAVA程序设计课程中各章节的程序实例。

import java.awt.*;
import java.applet.*;
//<applet code="simpleBanner" width=300 height= 200></applet>
 public class simpleBanner extends Applet implements Runnable {
   String msg = " A Simple Moving Banner.";
   Thread t = null;
   int state;
   boolean stopFlag;

    //Set colors and initialize thread.
   public void init() {
     setBackground(Color.cyan);
     setForeground(Color.red);
}

    //Start thread
  public void start () {
    t = new Thread(this);
    stopFlag =false;
    t.start();
  }

   //Entry point for the thread that runs the banner.
  public void run() {
    char ch;

   //Display banner
  for( ; ; ) {
    try {
      repaint();
      Thread.sleep(250);
      ch = msg.charAt(0);
      msg =msg.substring(1, msg.length());
      msg += ch;
      if(stopFlag)
        break;
   } catch(InterruptedException e) {}
 }
}
  //Pause the banner.
public void stop() {
  stopFlag = true;
  t = null;
}

  //Display the banner.
public void paint(Graphics g) {
  g.drawString(msg, 50, 30);
 }
}