框架窗口未关闭

Question

 /* my main class*/
//Magnify class run independently and close but when i call by main class it does not close the frame 
'''
    import javax.swing.*;
    import java.awt.event.*;
    public class MyLogin {
        private JFrame f = new JFrame("Login");
        private JButton bok = new JButton("OK");

        public MyLogin() {

            f.setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);
            f.getContentPane().add(bok);

            bok.addActionListener(new ActionListener() {
                public void actionPerformed(ActionEvent ae) {
                    f.dispose();
                    new Magnify();
                }
            });
            f.setSize(100,100);
            f.setVisible(true);
        }

        public static void main(String[] args) {
            new MyLogin();
        }
    }

/ *调用Magnify类* / // 强文本我已经尝试了Java中几乎所有可用的函数。 请提前帮助。

    //Java program to create a Magnifying tool 
    //using Java Robot class
    import java.awt.event.*; 
    import javax.swing.*; 
    import java.awt.*; 
    import java.awt.Graphics.*; 
    import java.awt.Robot;
    import java.awt.image.ImageObserver;

    public class Magnify extends JFrame{ 
     static Magnify main;
        Image i;

      Magnify(){


            setSize(300,300);
                    setLocationRelativeTo(null);
                    //dispose();
                    setVisible(true);
            work();

            }
        public void work() 
        { 

            try { 
                // create a robot 
                Robot r = new Robot(); 

                // while the frame is visible 

                while (isVisible()) { 
                    // get the position of mous


                    Point p = MouseInfo.getPointerInfo().getLocation(); 

                    // create a screen capture around the mouse pointer 
                    i = r.createScreenCapture(new Rectangle((int)p.getX() - 30, (int)p.getY() - 30, 150, 150)); 

                    // repaint the conatiner 
                    paint(getGraphics()); 

                } 

            } 
            catch (Exception e) { 
                System.err.println(e.getMessage()); 
            } 

        } 

        // paint function 
        public void paint(Graphics g) 
        {
            // draw the image 
            g.drawImage(i, 0, 0, 600, 600, (ImageObserver) this); 
                    setVisible(true);

        }   
    } 

'''// 强文本我已经尝试了Java中几乎所有可用的功能。 请提前帮助。 任何形式的帮助将不胜感激。我想当我在放大窗口上关闭时，它会很容易关闭。