给你发个透明窗口的例子...

public class TranslucentWindow extends JFrame  {      public TranslucentWindow()      {          super("TranslucentWindow");          setLayout(new GridBagLayout());          setSize(300, 200);          setLocationRelativeTo(null);          setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);          add(new JButton("I am a Button"));        //设置窗口的透明度为 55%          AWTUtilities.setWindowOpacity(this, 0.55f);      }        public static void main(String[] args)      {          //如果当前JDK不支持透明则退出          if (!AWTUtilities.isTranslucencySupported(AWTUtilities.Translucency.TRANSLUCENT))          {              System.err.println("Translucency is not supported");              System.exit(0);          }      TranslucentWindow tw = new TranslucentWindow();    tw.setVisible(true);      }  }