coloredboxes.java

Java 入门书的源码

//Copyright (c) 1998, Arthur Gittleman
//This example is provided WITHOUT ANY WARRANTY either expressed or implied.

// Debugging Exercise 11.8 -- Has Errors

          public class ColoredBoxes extends Applet {
              Color c;
              boolean done;
              public void start() {
                  done = false;
                  Thread t = new Thread(this);
                  t.start();
              }
              public void stop() {
                  done = true;
              }
              public void paint(Graphics g) {
                  g.drawRect(100,100,30,30);
              }
              public void run(){
                  while(! done) {
                       c = new Color((int)(255*Math.random()),                             
                                     (int)(255*Math.random()),
                                     (int)(255*Math.random()));
                       setForeground(c);
                       Thread.sleep(200);
                  }
              }
          }