Java-使用GridLayout和鼠标交互式JPanels创建JFrame

Question

（初学者）
嗨，很抱歉问这个问题，但是我总是有错误从哪里冒出来，我希望这个程序很简单。

package pixelpainter;
import java.awt.*;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.*;
import static javax.swing.JFrame.EXIT_ON_CLOSE;

public class PixelPainter extends JPanel {
int width = 20;
int height = 20;
int pixSize = 10;
Color bGColor = Color.WHITE;
Dimension pixDim = new Dimension(pixSize,pixSize);
private JPanel panelClicked = null;
JFrame frame= new JFrame();

/**
 * @param args the command line arguments
 */
public PixelPainter()
{
    initGUI();
}

public void initGUI() {

    frame.setLayout(new GridLayout(height, width, 0, 0));
    frame.setSize((height * pixSize), (width * pixSize));
    frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
    frame.pack();
    frame.setLocationRelativeTo(null);
    frame.setVisible(true);
    int[][] pixGrid = new int [width][height];

    for (int row = 0; row < height; row++)
    {
        for (int col = 0; col < width; col++)
        {
            JPanel pixel[][] = new JPanel[width][height];
            frame.add(pixel[row][col]);
            pixel[row][col].setBackground(bGColor);
            pixel[row][col].setPreferredSize(pixDim);
            pixel[row][col].setBorder(BorderFactory.createLineBorder(Color.BLACK));
            pixel[row][col].addMouseListener(new MouseAdapter()
            {
                @Override
                public void mouseClicked(MouseEvent click)
                {
                    JPanel selectedPixel = (JPanel) getComponentAt(click.getPoint());
                    if (selectedPixel == null || selectedPixel == PixelPainter.this)
                    {
                        return;
                    }
                    if (selectedPixel != null)
                    {
                        selectedPixel.setBackground(Color.BLACK);
                    }
                }
                @Override
                public void mousePressed(MouseEvent press)
                {

                }
            });
        }
    }
}

public static void main(String[] args){
    EventQueue.invokeLater(new Runnable(){
        @Override
                public void run(){
                    new PixelPainter().setVisible(true);
                }
            });     
    }

}

理想情况下，我会在填充颜色时使用2D数组JFrame，但显然它们必须是final或实际上是final。

Answer 1

我重新安排了你的代码，把类似的东西组合在一起。

下面是我创建的GUI。

我对您的代码做了以下更改。

由于model/view/controller模式，我将鼠标适配器代码拉到它自己的类中。分离关注点可以使GUI的每个部分更容易地正常工作。

代码是这样的。

package com.ggl.testing;

import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class PixelPainter implements Runnable {

    private JFrame frame;

    public static void main(String[] args) {
        EventQueue.invokeLater(new PixelPainter());
    }

    @Override
    public void run() {
        initGUI();
    }

    public void initGUI() {
        frame = new JFrame("Pixel Art");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        frame.add(createPixels());

        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    private JPanel createPixels() {
        int width = 30;
        int height = 20;

        JPanel panel = new JPanel();
        panel.setLayout(new GridLayout(height, width, 0, 0));

        for (int row = 0; row < height; row++) {
            for (int column = 0; column < width; column++) {
                PixelPanel pixelPanel = new PixelPanel();
                pixelPanel.addMouseListener(new ColorListener(pixelPanel));
                panel.add(pixelPanel);
            }
        }

        return panel;
    }

    public class PixelPanel extends JPanel {

        private static final long serialVersionUID = 8465814529701152253L;

        private static final int PIXEL_SIZE = 20;

        private Color backgroundColor;

        public PixelPanel() {
            this.backgroundColor = Color.WHITE;
            this.setBorder(BorderFactory.createLineBorder(Color.BLACK));
            this.setPreferredSize(new Dimension(PIXEL_SIZE, PIXEL_SIZE));
        }

        public Color getBackgroundColor() {
            return backgroundColor;
        }

        public void setBackgroundColor(Color backgroundColor) {
            this.backgroundColor = backgroundColor;
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);

            g.setColor(getBackgroundColor());
            g.fillRect(0, 0, getWidth(), getHeight());
        }
    }

    public class ColorListener extends MouseAdapter {

        private PixelPanel panel;

        public ColorListener(PixelPanel panel) {
            this.panel = panel;
        }

        @Override
        public void mousePressed(MouseEvent event) {
            if (event.getButton() == MouseEvent.BUTTON1) {
                panel.setBackgroundColor(Color.BLUE);
                panel.repaint();
            } else if (event.getButton() == MouseEvent.BUTTON3) {
                panel.setBackgroundColor(Color.WHITE);
                panel.repaint();
            }
        }
    }

}