当我将 X 推到关闭窗口时，为什么我的 AWT Java 窗口没有关闭？

Question

Hi I created this java code for AWT Window

package labelExample;
import java.awt.*;  
import java.awt.event.*;  
public class labelExample extends Frame implements ActionListener{  
    Frame f;
    TextField tf; Label l; Button b;  
    labelExample(){
        Frame f=new Frame("Label Example");
        tf=new TextField("www.google.de");  
        tf.setBounds(50,50, 150,20);  
        l=new Label();  
        l.setBounds(50,100, 250,20);      
        b=new Button("Find IP");  
        b.setBounds(50,150,60,30);  
        b.addActionListener(this);    
        add(b);add(tf);add(l);    
        setSize(400,400);  
        setLayout(null);  
        setVisible(true);
        f.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent we) {
                f.dispose(); // use dispose method 
             }
         }
         );
    }            
    public void actionPerformed(ActionEvent e) {  
        try{  
        String host=tf.getText();  
        String ip=java.net.InetAddress.getByName(host).getHostAddress();  
        l.setText("IP of "+host+" is: "+ip);  
        }catch(Exception ex){System.out.println(ex);}  
    }  
    public static void main(String[] args) {  
        new labelExample();  
    }  
    }

When I try to close the window by pushing the X button, nothing happens. The windows stays open. I made these changes my example code: public class labelExample extends Frame implements ActionListener{
I added new awt-frame f with name the "Label Example".
frame f; frame f=new Frame("Label Example"); And added this code to close the frame

f.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent we) {
         f.dispose(); // use dispose method 
         }
         }
         );

How do have change my code to fix this problem ?

Answer 1

I believe that in labelExample(){ ... } you should add a line setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); to close the window.