真假问题

Question

学编程时间不长，还没看设计模式，对下面这个程序中的 ok 真假的转换实在弄不明白我的理解是 当okButton点击时 ok 为真
当有对象调用showDialog时  ok 是先变假  最后return ok 的时候 不一直应该是假吗？
可我在后面的程序中有看到 showDialog好像有变真的时候  请高人指点。谢谢class PasswordChooser extends JPanel {
    private JTextField username;
    private JPasswordField password;
    private JButton okButton;
    private JDialog dialog;
    private boolean ok;    public PasswordChooser() {
        setLayout(new BorderLayout());        JPanel panel = new JPanel();
        panel.setLayout(new GridLayout(2, 2));
        panel.add(new JLabel("UserName: "));
        panel.add(username = new JTextField(""));
        panel.add(new JLabel("Password: "));
        panel.add(password = new JPasswordField(""));
        add(panel, BorderLayout.CENTER);        okButton = new JButton("OK");
        okButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent event) {
                ok = true;
                dialog.setVisible(false);
            }
        });        JButton cancelButton = new JButton("Cancel");
        cancelButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent event) {
                dialog.setVisible(false);
            }
        });        JPanel buttonPanel = new JPanel();
        buttonPanel.add(okButton);
        buttonPanel.add(cancelButton);
        add(buttonPanel, BorderLayout.SOUTH);
    }
    public void setUser(User u) {
        username.setText(u.getName());
    }
    public User getUser() {
        return new User(username.getText(), password.getPassword());
    }
    public boolean showDialog(Component parent, String title) {
        ok = false;
        Frame owner = null;        if(parent instanceof Frame)
            owner = (Frame) parent;
        else
            owner = (Frame) SwingUtilities.getAncestorOfClass(Frame.class, parent);        if(dialog == null || dialog.getOwner() != owner) {
            dialog = new JDialog(owner, true);
            dialog.add(this);
            dialog.setLocation(370, 300);
            dialog.getRootPane().setDefaultButton(okButton);
            dialog.pack();
        }
        dialog.setTitle(title);
        dialog.setVisible(true);
        return ok;
    }
}

Answer 1

private boolean ok; 初始 默认是 false

Answer 2

可我在后面的程序中有看到 showDialog好像有变真的时候看是先点击botton还是先调用showDialog！先后顺序不一样，自然结果也不一样

Answer 3

okButton.addActionListener(new ActionListener() { 
            public void actionPerformed(ActionEvent event) { 
                ok = true; 
                dialog.setVisible(false); 
            } public boolean showDialog(Component parent, String title) { 
        ok = false; 
        Frame owner = null; 根据这2段代码，显示了当ok button按下是ok为true,但下面段程序启动时ok为false

Answer 4

那大家的意思是 当启动showDialog的时候 ok一直是假？
但要是这样的话 
private class ConnectListener implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            if(pc == null)
                pc = new PasswordChooser();
            pc.setUser(new User("\"Guest\"", null));
            if(pc.showDialog(ExchangeF.this, "Connect")) {
                User u = pc.getUser();
                jta.append("Username: " + u.getName() + ", Password: " +
                    new String(u.getPassword()) + "\n");
            }
        }
    }  这个里面的红色那句不是应该没有为真的时候了？ 可是应该有啊