PaintComponent 不在 JPanel 上绘制 BufferedImage 网格

Question

我为 TicTacToe 游戏创建了一个 600 x 600 网格，但每次我尝试获取图像（使用 getImg() 方法）时，它都会显示白屏。 JPanel的背景是暗灰色的，它既不绘制网格，也不显示JPanel背景。

这是代码，我没有尝试过任何东西

PanelManager.java

package TicTacToe.display.panel;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;

import javax.imageio.ImageIO;
import javax.swing.JPanel;

public class PanelManager extends JPanel implements Runnable{
    
    Thread t;
    
    BufferedImage grid;
    
    public PanelManager() {
        
        this.setPreferredSize(new Dimension(600,600));
        this.setBackground(Color.darkGray);
        this.setDoubleBuffered(true);
        
        this.startThread();
}
    public void getImg() {
        try {
            grid = ImageIO.read(getClass().getResourceAsStream("/TicTacToe/grid/grid.png"));
        }
        catch (IOException e) {
            e.printStackTrace();
        }
    }
    public void startThread() {
        
        t = new Thread(this);
        t.start();
        
    }
    public void paintComponent(Graphics g) {
        
        super.paintComponent(g);
        
        Graphics2D g2 = (Graphics2D)g;
        
        g2.drawImage(grid,300,300,600,600,null);
        
        g2.dispose();
        
    }
    public void update() {
        
    }
    public void run() {
        while(t != null) {
                update();
                try {
                    Thread.sleep(10);
                }
                catch (Exception e) {}
                repaint();
                
        }        
    }

}

FrameManager.java

package TicTacToe.display;

import javax.swing.JFrame;
import javax.swing.WindowConstants;

import TicTacToe.display.panel.PanelManager;

public class FrameManager {
    public static void main(String[] args) {
        
        JFrame f = new JFrame();
        PanelManager pm = new PanelManager();
        
        f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        f.setTitle("TicTacToe Windowed Edition");
        f.setResizable(false);
        f.setVisible(true);
        f.setSize(600,600);
        f.setLocationRelativeTo(null);
        
        
        f.add(pm);
    }
}

Answer 1

读了一下代码后，我意识到我没有使用 getImg(); 方法，我所要做的就是在 PanelManager() 中添加一行代码代码>构造函数如下所示：-

public PanelManager() {
        
        this.setPreferredSize(new Dimension(600,600));
        this.setBackground(Color.darkGray);
        this.setDoubleBuffered(true);
        
        this.getImg();
        this.startThread();
}