在paintComponent绘制形状上添加按钮

Question

My program is consist of two classes(test and paintClass) in different files. In the paintClass class I draw a 5x5 square board by using paintComponent method. I want to add buttons in each small square in the big square. When I run the code I don't get any buttons. I want to have 25(5x5) buttons by using jpanel on a shape drawn by paintComponent. Is this possible? If it is, how I can do it?

EDIT : The problem was the loop. Number had a default value of 0 so the loop didn't work. I defined number at the beginning. It solved the problem. Also one of the invervals were wrong. I changed j = 0 with j = 1.

import javax.swing.*;
import java.awt.*;

public class test
{

   public static void main(String[] args) 
   {

       JFrame frame = new JFrame("buttons");
       frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       frame.setSize(250,250);
       PaintClass paint = new PaintClass();
       paint.repaint();
       f1.getContentPane().add(paint);
       frame.pack();
       frame.setVisible(true);
    }
}



import javax.swing.*;
import java.awt.*;

public class PaintClass extends JPanel
{
    private Graphics g;
    private int interval,side,number;
    private JButton button;

    public PaintClass() 
    {
        number = 5;
        button = new JButton();
        setLayout(new GridLayout(5,5));
        for(int i = 0; i <= number - 1; i++)
        {
            for(int j = 1; j <= number - 1; j++)
            {
                button = new JButton();//ADDED
                button.setBounds(i * interval, 0, interval, interval);
                add(button);
            }
            button = new JButton();//ADDED
            button.setBounds(0, i * interval, interval, interval);
            add(button);
        }
    }

    public void paintComponent(Graphics g)
    {
        super.paintComponent(g);
        this.repaint();
        side = 250;
        number = 5;
        interval = side / number;
        g.drawRect(0,0, side, side);

        for(int i = 0; i <= number - 1; i++)
        {
            for(int j = 0; j <= number - 1; j++)
            {
                 g.drawLine(i * interval, 0, i * interval, side);
            }
            g.drawLine(0, i * interval, side, i * interval);
        }

    }   
}

Answer 1

private int interval,side,number;

Number has a default value of 0.

for(int i = 0; i <= number - 1; i++)

Since number is 0, your loop will never execute.

Once you do this the buttons will be added to the panel but they will cover your custom painting. To see background lines you just need to set the background of the panel to Color.BLACK and then create your GridLayout with a gap between the components. Read the API for the method to use.

Answer 2

Choose one or the other: either add the buttons using the GridLayout, or paint the buttons using paintComponent. If the former, you should a) define the loop constraint (right now it is 0) b) create a new JButton for every loop (your code currently reuses the instance) and c) register the appropriate ActionListener to respond to events. If the latter, you need to register the appropriate listener (like MouseListener ) to respond to user generated events.