定时器延迟不能正常工作

Question

EDITTED POST:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Examp{
JFrame field;
JPanel squares[][] = new JPanel[10][6];

public Examp(){
    field = new JFrame("Football Game");
    field.setSize(600, 800);
    field.setLayout(new GridLayout(10, 6));

    for (int i = 0; i < 10; i++)
    {
        for (int j = 0; j < 6; j++)
        {
            squares[i][j] = new JPanel();
            if (j == 2 || j == 3)
            {
                if (i == 0)
                    squares[i][j].setBackground(Color.RED);
                else if (i == 9)
                    squares[i][j].setBackground(Color.BLUE);
                else
                    squares[i][j].setBackground(Color.GREEN);
            }
            else
            {
                squares[i][j].setBackground(Color.GREEN);
            }
            field.add(squares[i][j]);
        }
    }

    field.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    field.setVisible(true);
}

public void place(int i,int j){
    ImageIcon ballIcon = new ImageIcon("C:\\Users\\Pamvotis\\Desktop\\Project\\img\\icon.png");
    JLabel ball = new JLabel(ballIcon);
    squares[i][j].add(ball);

    field.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    field.setVisible(true);
}

public void clear(){
    for (int i = 0; i < 10; i++)
    {
        for (int j = 0; j < 6; j++)
        {
            squares[i][j].removeAll();
        }
    }
    field.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    field.setVisible(true);
}

public static void main(String[] args){
    Examp football = new Examp();
    football.place(2,3);
    Timer timer = new Timer(1000, new ActionListener() {
      @Override
      public void actionPerformed(ActionEvent e) {
          football.clear();
          System.out.println("happened");
        }
    });
  timer.setRepeats(false);
  timer.start();

}

}

So I have edited and tried to simplify the code so you can understand what I am asking better I apologize about before.

Basically what I want is to clear the field from all icons after 1 sec (I want to make a football game so I'm using this to see how it would work on a bigger scale where I would remove everything after each round to add the new positions). My problem is that the the method clear() doesn't seem to get executed when it is in the Timer (if I do it outside it gets executed just fine). My System.out.println(...) gets executed just fine as well in the Timer with the proper delay so I really don't get what the problem is. Can anyone help me?

Answer 1

The clear(...) method is in fact very likely executed, and if you put a println within it, you'll know for sure. The question is, is it executing on the correct object?

I'm guessing that your Game class has its own Graphics object (a terrible class name by the way since it clashes directly with the java.awt.Graphics class, and that's the one that needs to have its state changed. A likely solution is to give Game a method that allows outside classes the ability to change its state.

For better answers though, please post a better more informative question, one with more pertinent code.

Answer 2

Maybe the better is to made field int counter expample int counter =1; and in timer task you can decrease counter by 1. so counter will have new value 0. And somewhere where you need that you can check does counter have value 0 if yes you can call your method football.clear();

Update:

   public int counter=1;

   *********

   Timer timer = new Timer(1000, new ActionListener() {
   @Override
   public void actionPerformed(ActionEvent e) {
         counter--;
     }
   });
 timer.start();
}

***********

if(counter==1){
  football.clear();
  System.out.println("happened");
}