如何刷新 JFrame

Question

so I want to make some sort of Tic tac toe, and I'm not sure if the rest of my code is correct (I'm obviously not done yet) but I think that the Problem is that the JFrame doesn't Refresh and I don't know how to do that so how to Refresh a frame?

package pack1;

import java.awt.GridLayout;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;

public class Gui {


public  Gui() {
     Var.jf = new JFrame();
      Var.jf.setSize(Var.screenwidth, Var.screenheight);

      Var.button1 = new JButton(Var.arr[Var.a]);
      Var.jf.add(Var.button1);
      Var.button2 = new JButton(Var.arr[Var.b]);
      Var.jf.add(Var.button2);
      Var.button3 = new JButton(Var.arr[Var.c]);
      Var.jf.add(Var.button3);
      Var.button4 = new JButton(Var.arr[Var.d]);
      Var.jf.add(Var.button4);
      Var.button5 = new JButton(Var.arr[Var.e]);
      Var.jf.add(Var.button5);
      Var.button6 = new JButton(Var.arr[Var.f]);
      Var.jf.add(Var.button6);
      Var.button7 = new JButton(Var.arr[Var.g]);
      Var.jf.add(Var.button7);
      Var.button8 = new JButton(Var.arr[Var.h]);
      Var.jf.add(Var.button8);
      Var.button9 = new JButton(Var.arr[Var.i]);
      Var.jf.add(Var.button9);
      Var.jf.setLayout(new GridLayout(3,3,10,10));
      Var.button1.addActionListener(new KeyListiner());

      Var.jf.setTitle("Tic tac toe");
      Var.jf.setVisible(true);
      Var.jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      Var.jf.setLayout(null);
      Var.jf.setLocationRelativeTo(null);
      Var.jf.setResizable(false);
   }
}

---

 package pack1;

 import javax.swing.*;

 public class Var {
 static JFrame jf;
 static JButton button1;
 static JButton button2;
 static JButton button3;
 static JButton button4;
 static JButton button5;
 static JButton button6;
 static JButton button7;
 static JButton button8;
 static JButton button9;
 static  int a = 2;
 static  int b = 2;
 static int c = 2;
 static int d = 2;
 static int e = 2;
 static int f = 2;
 static int g = 2;
 static int h = 2;
 static int i = 2;

 static int screenwidth = 900, screenheight = 900;
 static String[]arr = new String[3];{

 arr[0] = "X";
 arr[1] = "O";
 arr[2] = " ";
 }}

---

package pack1;

import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class KeyListiner implements ActionListener {

@Override
public void actionPerformed(ActionEvent e) {
    if(e.getSource()==Var.button1);
    
     
     System.out.println(Var.a);
     Var.a= 0 ;
     
}
}

If I didn't explained something correctly or something like this just tell me.

Answer 1

You may have several buttons but ony one of them has a keylistener. That means you would have to move the focus to the one button and press a key. Tricky as the UI does not indicate such a limitation.

Try to take this with an event-driven approach. Attach an ActionListener to every button. Inside this actionlistener you change the board as required, then call the repaint() method (that does not really repaint but mark this component to be repainted), and EXIT your method. Unless you exit the method which is running on the Event Dispatcher Thread no UI updates will happen.

If you want to continue doing your stuff while the UI updates you need to create your own Thread.