在Java中将单击的像素的颜色更改为红色？

Question

当我单击图像的像素时，我希望将该像素更改为红色。我对 Java 中的图形没有太多经验，所以我可能会遗漏一些必不可少的东西。感谢您提供的任何帮助。

public class Main {

static BufferedImage image;

public static void main(String[] args) {

    try {

        image = ImageIO.read(new File("pic.png"));

    } catch (IOException e) {

        e.printStackTrace();

    }

    JFrame frame = new JFrame();

    frame.getContentPane().setLayout(new FlowLayout());

    JLabel label = new JLabel(new ImageIcon(image));

    // change the pixels to random colors when hovering over them

    label.addMouseListener(new MouseAdapter() {

        @Override

        public void mouseClicked(MouseEvent e) {

            super.mouseClicked(e);

            System.out.println("CLICKED: " + "(" + e.getX() + "," + e.getY() + ")");

            //getColorOfPixel(e.getX(), e.getY());

            changeColorOfPixel(e.getX(), e.getY());

        }

    });

    frame.getContentPane().add(label);

    frame.pack();

    frame.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);

    frame.setVisible(true);

}

public static void changeColorOfPixel(int xCoordinateClicked, int yCoordinateClicked) {

    int width = image.getWidth();

    int height = image.getHeight();

    int[][] pixels = new int[width][height];

    for(int i = 0; i < width; i++) {

        for(int j = 0; j < height; j++) {

            pixels[i][j] = image.getRGB(xCoordinateClicked, yCoordinateClicked);

            if(i == xCoordinateClicked && j == yCoordinateClicked) {

                Color newColor = Color.RED;

                image.setRGB(xCoordinateClicked, yCoordinateClicked, newColor.getRGB());

            }

        }

    }

}

}

Answer 1

您需要frame.repaint();在像素颜色更改后调用，因此例如只需更改这样的MouseAdapter定义（假设frame也将定义为static：&nbsp; &nbsp; label.addMouseListener(new MouseAdapter() {&nbsp; &nbsp; &nbsp; &nbsp; @Override&nbsp; &nbsp; &nbsp; &nbsp; public void mouseClicked(MouseEvent e) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; super.mouseClicked(e);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; System.out.println("CLICKED: " + "(" + e.getX() + "," + e.getY() + ")");&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; image.setRGB(e.getX(), e.getY(), Color.RED.getRGB());&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; frame.repaint();&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; });