私は個人的に透明なウィンドウを優先してウィンドウの形状を捨てます。あなたがやろうとしていることは単純です...
そして閉じるボタンで（左下を見てください）
「ウィンドウ」の境界を示すため、画像の周りの赤い境界線は意図的なものです。
これは Java 1.7 または Java 1.6_10+ に依存しており、コードにチェックがあります。
public class TransparentFrame {
public static void main(String[] args) {
new TransparentFrame();
}
public TransparentFrame() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Exception ex) {
}
JFrame frame = new JFrame("Testing");
frame.setUndecorated(true);
frame.setContentPane(new ContentPane());
String version = System.getProperty("java.version");
System.out.println(version);
if (version.startsWith("1.7")) {
frame.setBackground(new Color(0, 0, 0, 0));
} else if (version.startsWith("1.6")) {
if (supportsPerAlphaPixel()) {
setOpaque(frame, false);
} else {
System.out.println("Per Pixel Alphering is not support with Java " + version);
System.exit(1);
}
} else {
System.out.println("Per Pixel Alphering is not support with Java " + version);
System.exit(1);
}
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new ImagePane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public static boolean supportsPerAlphaPixel() {
boolean support = false;
try {
Class<?> awtUtilsClass = Class.forName("com.sun.awt.AWTUtilities");
support = true;
} catch (Exception exp) {
}
return support;
}
public static void setOpaque(Window window, boolean opaque) {
try {
Class<?> awtUtilsClass = Class.forName("com.sun.awt.AWTUtilities");
if (awtUtilsClass != null) {
Method method = awtUtilsClass.getMethod("setWindowOpaque", Window.class, boolean.class);
method.invoke(null, window, opaque);
}
} catch (Exception exp) {
}
}
public class ContentPane extends JPanel {
public ContentPane() {
setOpaque(false);
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.RED);
g.drawRect(0, 0, getWidth() - 1, getHeight() - 1);
}
}
public class ImagePane extends JPanel {
private BufferedImage background;
private BufferedImage offImage;
private Ellipse2D offButton;
private boolean mouseIn;
public ImagePane() {
setOpaque(false);
try {
background = ImageIO.read(new File("tamagotchi400.png"));
offImage = ImageIO.read(new File("powerSmall.png"));
} catch (IOException ex) {
ex.printStackTrace();
}
offButton = new Ellipse2D.Float(212, 330, 25, 25);
MouseAdapter handler = new MouseAdapter() {
@Override
public void mouseClicked(MouseEvent e) {
if (e.getClickCount() == 1 && e.getButton() == MouseEvent.BUTTON1) {
if (offButton.contains(e.getPoint())) {
Window window = SwingUtilities.getWindowAncestor(ImagePane.this);
if (window != null) {
window.dispose();
}
}
}
}
@Override
public void mouseMoved(MouseEvent e) {
Cursor cursor = Cursor.getDefaultCursor();
if (offButton.contains(e.getPoint())) {
cursor = Cursor.getPredefinedCursor(Cursor.HAND_CURSOR);
}
setCursor(cursor);
}
@Override
public void mouseEntered(MouseEvent e) {
mouseIn = true;
repaint();
}
@Override
public void mouseExited(MouseEvent e) {
mouseIn = false;
repaint();
}
};
addMouseListener(handler);
addMouseMotionListener(handler);
}
@Override
public Dimension getPreferredSize() {
return background == null ? new Dimension(400, 400) : new Dimension(background.getWidth(), background.getHeight());
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (background != null) {
Graphics2D g2d = (Graphics2D) g.create();
int x = (getWidth() - background.getWidth()) / 2;
int y = (getHeight() - background.getHeight()) / 2;
g2d.drawImage(background, x, y, this);
if (mouseIn && offImage != null) {
g2d.drawImage(offImage, (int) offButton.getX(), (int) offButton.getY(), this);
}
g2d.dispose();
}
}
}
}
あなたの最初の質問が理解できませんでした。私の英語はあまり上手ではなく、これが理由かもしれません。
2 番目の質問ですが、TrayIcon について何か試したことはありますか? ご覧ください: http://docs.oracle.com/javase/tutorial/uiswing/misc/systemtray.htmlおよびhttp://docs.oracle.com/javase/6/docs/api/java/awt/ TrayIcon.html