desktoppane无反应，有无人帮帮我

package chen.java123.view;

import java.awt.BorderLayout;
import java.awt.EventQueue;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JMenuBar;
import javax.swing.JMenu;
import javax.swing.JMenuItem;
import java.awt.Color;
import java.awt.Component;
import java.awt.Container;

import javax.swing.JLabel;
import javax.swing.ImageIcon;
import javax.swing.JDesktopPane;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

public class MainView extends JFrame {

private JPanel contentPane;
private Component jpanel;
private JFrame frame;
JDesktopPane desktopPane;


public static void main(String[] args) {
    EventQueue.invokeLater(new Runnable() {
        public void run() {
            try {
                MainView frame = new MainView();
                frame.setVisible(true);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    });
}

public MainView() {
    setResizable(false);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setBounds(100, 100, 900, 600);
    this.setLocationRelativeTo(null);
    contentPane = new JPanel();
    contentPane.setBackground(Color.BLACK);
    contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
    setContentPane(contentPane);
    contentPane.setLayout(null);
    
    JMenuBar menuBar = new JMenuBar();
    menuBar.setBounds(0, 0, 896, 36);
    contentPane.add(menuBar);
    
    JMenu mnNewMenu = new JMenu("基本数据维护");
    mnNewMenu.setForeground(Color.BLUE);
    menuBar.add(mnNewMenu);
    
    JMenu mnNewMenu_2 = new JMenu("图书类别管理");
    mnNewMenu.add(mnNewMenu_2);
    
    JMenuItem mntmNewMenuItem_1 = new JMenuItem("图书类别的新增");
    mntmNewMenuItem_1.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            BookTypeAdd booktypeadd =new BookTypeAdd();
            desktopPane.add(booktypeadd);
            booktypeadd.setVisible(true);
        }
    });
    mnNewMenu_2.add(mntmNewMenuItem_1);
    
    JMenuItem mntmNewMenuItem_2 = new JMenuItem("图书类别的维护");
    mnNewMenu_2.add(mntmNewMenuItem_2);
    
    JMenu mnNewMenu_3 = new JMenu("图书管理");
    mnNewMenu.add(mnNewMenu_3);
    
    JMenuItem mntmNewMenuItem_3 = new JMenuItem("图书新增");
    mnNewMenu_3.add(mntmNewMenuItem_3);
    
    JMenuItem mntmNewMenuItem_4 = new JMenuItem("图书维护");
    mnNewMenu_3.add(mntmNewMenuItem_4);
    
    JMenuItem mntmNewMenuItem = new JMenuItem("安全退出");
    mnNewMenu.add(mntmNewMenuItem);
    
    JMenu mnNewMenu_1 = new JMenu("关于我们");
    mnNewMenu_1.setForeground(Color.BLUE);
    menuBar.add(mnNewMenu_1);
    
    JMenuItem mntmNewMenuItem_5 = new JMenuItem("关于我们");
    mnNewMenu_1.add(mntmNewMenuItem_5);
    
    JPanel panel = new JPanel();
    panel.setBounds(169, 118, 475, 308);
    contentPane.add(panel);
    
    JLabel lblNewLabel = new JLabel("");
    lblNewLabel.setIcon(new ImageIcon(MainView.class.getResource("/images/OIP-C.jpg")));
    panel.add(lblNewLabel);
    desktopPane = new JDesktopPane();
    desktopPane.setBounds(67, 504, 765, -418);
    contentPane.add(desktopPane);
}

}

麻烦把问题可以描述的在详细点，这样才能排查

跟我要做的好像有点像。。。😀