主屏幕上的JFrame复制

Question

My code is duplicating the creation of the main screen when I hit the button of the search..the search event should only open one new frame with a textbox to type query. The creation of another frame causes this duplication or is this some sort of bug? I tryed to use the mainFrame to upload the date of the searchPane (p1 in the code) but when I do this, this solves my problem of the window, but the defaultCloseOperation() on the Search Windows causes the close of the entire program - how may I solve this situtation?

thanks in advance

SearchScreen

import java.awt.Color;
import java.awt.GridLayout;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class SearchScreen extends MainScreen{

    JButton btsearch;
    JLabel lbsearch;
    protected JTextField txtsearch;
    JPanel p1;
    protected JFrame searchFrame = new JFrame();

    public SearchScreen(){

    //Button Creation
        btsearch= new JButton("Search");

    //Label Creation
        lbsearch= new JLabel("Type Keywords in english to be searched below:");

    //TextBox   
        txtsearch= new JTextField();

    //Pane Creation 
        p1=new JPanel();
            p1.setBackground(Color.gray);

    //Pane Components
        p1.add(lbsearch);
            p1.add(txtsearch);
                p1.add(btsearch);

    //JFrame Layout Setup   
        p1.setLayout(new GridLayout(3,3));

            btsearch.setEnabled(true);

    //Adding JPaneel    
        searchFrame.add(p1);

    //JFrame Setup
        searchFrame.setTitle("SHST");
            searchFrame.setSize(400, 400);
                searchFrame.setVisible(true);
                    searchFrame.setDefaultCloseOperation(1);

    }

}

MainScreen

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;

import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JTabbedPane;

public class MainScreen implements ActionListener {


    JMenuBar bar;
    JMenu file, register;
    JMenuItem close, search;
    JPanel entrance = new JPanel();
    JFrame mainFrame = new JFrame();

    public MainScreen()
    {

        bar= new JMenuBar();
        file= new JMenu("File");
            register= new JMenu("Search");

        close= new JMenuItem("Close");
            close.addActionListener(this);

        search= new JMenuItem("Request Query");
            search.addActionListener(this);

        //mainFrame Setup
        bar.add(file);
            bar.add(register);
                file.add(close);
                    register.add(search);

            mainFrame.setExtendedState(mainFrame.getExtendedState() | mainFrame.MAXIMIZED_BOTH); 
                mainFrame.setTitle("SHST");
                    mainFrame.setJMenuBar(bar);
                        mainFrame.setDefaultCloseOperation(0);
                            mainFrame.setVisible(true);

                             WindowListener J=new WindowAdapter(){
                                    public void windowClosing(WindowEvent e){
                                    System.exit(0);
                                    }
                                }; 

                                mainFrame.addWindowListener(J);

}

    public void actionPerformed(ActionEvent e){
        if(e.getSource()==close){
            System.exit(0);
    }

            if(e.getSource()==search){
                SearchScreen s= new SearchScreen();

            }

public static void main (String[] args){

        MainScreen m= new MainScreen();

    }

        }

Answer 1

Your issue is here

 if(e.getSource()==search){
                    SearchScreen s= new SearchScreen();

                }

Using inheritance implementation is dangereous, a SearchScreen is a MainScreen then the constructor of this class is always called.