主屏幕上的JFrame重复

Question

当我点击搜索按钮时，我的代码重复了主屏幕的创建。搜索事件应该只打开一个带有文本框的新框架来键入查询。另一个框架的创建会导致这种重复或者这是一种错误？我尝试使用mainFrame上传searchPane的日期（代码中的p1），但是当我这样做时，这解决了我的窗口问题，但Search Windows上的defaultCloseOperation（）会导致整个程序关闭 - 我怎么能解决这个问题？

在此先感谢

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

你的问题就在这里

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

       } 

使用继承的实现是dangereous，一个SearchScree n是MainScreen那么这个类的构造函数总是被调用。