Question

有一个类有静态方法：ChangePanel，它会将静态JPanel的内容更改为新内容。 Frame是静态JPanel的变量名。

 public static void ChangePanel(JPanel jp)
    {

        Javaassignment1b.Driver.Frame.getContentPane().removeAll();

        Javaassignment1b.Driver.Frame.add(jp);

        Javaassignment1b.Driver.Frame.validate();

    }

此静态方法在JPanel上实现时按预期工作，该功能由actionlistener添加。

示例

public class AdminLoginPanel extends JPanel
{
    AdminLoginPanel()
    {         
        pwlabel = new JLabel("Password");
        pwfield = new JPasswordField(20);
        loginbutton = new JButton("Login");

        loginbutton.addActionListener(new LoginButtonListener());

        add(pwlabel);
        add(pwfield);
        add(loginbutton);

     }

    private class LoginButtonListener implements ActionListener 
    {
         public void actionPerformed(ActionEvent event)
        {

            char[] password = pwfield.getPassword();

            //convert from char array to String
            String password2 = new String(password);

            admin = new Admin();

            if (admin.checkPassword(password2))
            {
                //show Admin panel
                //works in this case
                AdminMenuPanel amp = new AdminMenuPanel();
                Utility.ChangePanel(amp);


            }
            else
            {
                //text box appear to state password is incorrect
                ErrorMessagePanel emp = new ErrorMessagePanel("Wrong password, please try again");


            }


        }





    }



    JLabel pwlabel;
    JPasswordField pwfield;
    JButton loginbutton;
    Admin admin;

}

当我尝试通过JOptionPane的返回值更改静态JPanel的内容时，我不明白为什么它不起作用

public class RetryPanel extends JPanel
{
    RetryPanel()
    {
        jp = new JOptionPane();

        //reply will be 1 for No , 0 for yes
        int reply = JOptionPane.showConfirmDialog(null,"Would you like to start a new game ???","Message Title",JOptionPane.YES_NO_OPTION );

        if ( reply == 0)
        {
            //player wants to play a new game , retry


        }
        else
        {
            //player wants to quit
            //doesnt work in this case
            SelectAdminUserPanel saup = new SelectAdminUserPanel();
            Utility.ChangePanel(saup);
        }

    }

    JOptionPane jp;
}

使用调试器显示我的代码已执行但是它并没有改变静态Jpanel内容，我怀疑它可能与线程有关，有人可以帮我解决这个问题

注意：我知道CardLayout是更换JPanel的更好选择，但由于遗留原因，我需要弄清楚

由于

静态JPanel内容未更新

0 个答案: