JOptionPane.java 文件源码

private JDialog createDialog(Component parentComponent, String title,
        int style)
        throws HeadlessException {

    final JDialog dialog;

    Window window = JOptionPane.getWindowForComponent(parentComponent);
    if (window instanceof Frame) {
        dialog = new JDialog((Frame)window, title, true);
    } else {
        dialog = new JDialog((Dialog)window, title, true);
    }
    if (window instanceof SwingUtilities.SharedOwnerFrame) {
        WindowListener ownerShutdownListener =
                SwingUtilities.getSharedOwnerFrameShutdownListener();
        dialog.addWindowListener(ownerShutdownListener);
    }
    initDialog(dialog, style, parentComponent);
    return dialog;
}