給你發個透明窗口的例子...

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"));


    //設置窗口的透明度為 55%
    AWTUtilities.setWindowOpacity(this, 0.55f);
}

public static void main(String[] args)
{
    //如果當前JDK不支持透明則退出
    if (!AWTUtilities.isTranslucencySupported(AWTUtilities.Translucency.TRANSLUCENT))
    {
        System.err.println("Translucency is not supported");
        System.exit(0);
    }

    TranslucentWindow tw = new TranslucentWindow();
    tw.setVisible(true);
}

}</pre>