一个挥杆新手，想做一个小小的移动眼睛Java GUI练习却卡住了

我想实现一个面板，绘制两只眼睛，根据鼠标光标是在眼睛上方、内部还是下方向上、中间还是向下移动。我首先使用这个代码来制作眼睛：

public class EyesPanel extends JPanel implements ActionListener {
    // images
    public void paintComponent(Graphics g) {
        super.paintComponents(g);
        g.drawOval(130, 100, 120, 120);
        g.drawOval(250, 100, 120, 120);
        g.fillOval(175, y, 30, 30);   // x: 175  y: 145
        g.fillOval(295, y, 30, 30);   // x: 295  y: 145
    }

然后是时候添加事件监听器来让这个类工作了，但这里是我坚持的部分。我知道如何使图形移动（ActionListener），我知道如何实现MouseInputListener（扩展MouseInputListener）。然而，将这两者结合在一起让我感到沮丧。谁能告诉我怎么做，给我一个示例代码真的很有帮助

以下是迄今为止我的代码，不是一个运行正常且完整的代码：

public class EyesPanel extends JPanel implements ActionListener {
    private JPanel panel;
    private int y;
    private int dy;
    private Timer t;
    private Mouse move;

    public EyesPanel() {
        dy = 5;
        y = 145;

        // mouse detector
        this.addMouseListener(new Mouse());
        this.addMouseMotionListener(new Mouse());

        // Timer 
        t = new Timer(100, this);
    }

    // images
    public void paintComponent(Graphics g) {
        super.paintComponents(g);
        g.drawOval(130, 100, 120, 120);
        g.drawOval(250, 100, 120, 120);
        g.fillOval(175, y, 30, 30);   // x: 175  y: 145
        g.fillOval(295, y, 30, 30);   // x: 295  y: 145
    }

    public void actionPerformed(ActionEvent event) {
        moveDown();     //➜ not complete, don't know how to implement
    }

    // move up
    private void moveUp() {
        if (move.move() == 1) {
            t.start();
            y = y + dy;
            repaint();
        } else {
            t.stop();
        }
    }

    // move down
    private void moveDown() {
        if (move.move() == -1) {
            t.start();
            y = y - dy;
            repaint();
        } else {
            t.stop();
        }
    }
    // ➜ not complete, trying, but no clue
}

我的鼠标事件类：

public class Mouse extends MouseInputAdapter {
    private int y;

    public void mouseEntered(MouseEvent event) {
        JPanel pane =  (JPanel) event.getSource();
        y = pane.getHeight();      // ➜ not complete
    }
}

---

您正在寻找方法

mouseMoved

而不是

mouseEntered

使您的类像这样，并且您的gota从super.paintComponents（g）上取下s

导入java.awt.Graphics；
导入java.awt.event.ActionEvent；
导入java.awt.event.ActionListener；
导入java.awt.event.MouseEvent；
导入java.awt.event.MouseMotionListener；
导入java.util.Timer；
导入javax.swing.JPanel；
公共类EyesPanel扩展JPanel实现ActionListener、MouseMotionListener{
私人JPanel小组；
私营企业；
私家侦探；
私人定时器t；
公共事务委员会（）{
dy=5；
y=145；
//鼠标检测器
this.addMouseMotionListener（this）；
//计时器
}
//图像
公共组件（图形g）{
超级组件（g）；
g、 drawOval（130100120120）；
g、 drawOval（250100120120）；
g、 圆角（175，y，30，30）；/x:175 y:145
g、 圆角（295，y，30，30）；/x:295 y:145
}
//上移
// ➜ 不完整，尝试，但没有线索
@凌驾
已执行的公共无效操作（操作事件arg0）{
//TODO自动生成的方法存根
}
@凌驾
公共无效鼠标标记（鼠标事件arg0）{
//TODO自动生成的方法存根
}
@凌驾
public void mouseMoved（MouseEvent arg0）{
//TODO自动生成的方法存根
System.out.println（arg0.getY（））；
if（arg0.getY（）>101&&arg0.getY（）<187）
y=arg0.getY（）；
重新油漆（）；
}
}

让眼睛跟随光标的数学原理并不复杂

下面是我的GUI的外观

我创建了一个Eye类来固定外眼窝的中心和内眼球的中心

我创建了一个MovingEyes类来创建JFrame，并创建了一个DrawingPanel类来在DrawingPanel上绘制眼睛。我在MovingEyes类的构造函数中创建了眼睛数组来容纳2只眼睛

DrawingPanel类的paintComponent方法除了画眼睛之外，什么也不做。黑眼球中心的计算在另一类中进行。我创建了两种方便的方法，这样我就可以画一个圆，并使用圆心和半径填充一个圆

EyeballListener类执行两个黑色眼球的计算。我们计算从眼窝中心到鼠标指针的线的θ角（弧度）。然后，我们使用θ角和眼球距离计算黑眼球的x和y位置

这是密码

package com.ggl.testing;

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

public class MovingEyes implements Runnable {

    private static final int drawingWidth = 400;
    private static final int drawingHeight = 400;
    private static final int eyeballHeight = 150;
    private static final int eyeballWidthMargin = 125;
    private static final int eyeballOuterRadius = 50;
    private static final int eyeballInnerRadius = 20;

    private DrawingPanel drawingPanel;

    private Eye[] eyes;

    private JFrame frame;

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

    public MovingEyes() {
        this.eyes = new Eye[2];
        this.eyes[0] = new Eye(new Point(eyeballWidthMargin, eyeballHeight));
        this.eyes[1] = new Eye(new Point(drawingWidth - eyeballWidthMargin,
                eyeballHeight));
    }

    @Override
    public void run() {
        frame = new JFrame("Moving Eyes");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        drawingPanel = new DrawingPanel();
        frame.add(drawingPanel);

        frame.pack();
        frame.setLocationByPlatform(true);
        frame.setVisible(true);
    }

    public class DrawingPanel extends JPanel {

        private static final long serialVersionUID = -2977860217912678180L;

        public DrawingPanel() {
            this.addMouseMotionListener(new EyeballListener());
            this.setBackground(Color.WHITE);
            this.setPreferredSize(new Dimension(drawingWidth, drawingHeight));
        }

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

            g.setColor(Color.BLACK);

            for (Eye eye : eyes) {
                drawCircle(g, eye.getOrigin(), eyeballOuterRadius);
                fillCircle(g, eye.getEyeballOrigin(), eyeballInnerRadius);
            }
        }

        private void drawCircle(Graphics g, Point origin, int radius) {
            g.drawOval(origin.x - radius, origin.y - radius, radius + radius,
                    radius + radius);
        }

        private void fillCircle(Graphics g, Point origin, int radius) {
            g.fillOval(origin.x - radius, origin.y - radius, radius + radius,
                    radius + radius);
        }

    }

    public class Eye {
        private final Point origin;
        private Point eyeballOrigin;

        public Eye(Point origin) {
            this.origin = origin;
            this.eyeballOrigin = origin;
        }

        public Point getEyeballOrigin() {
            return eyeballOrigin;
        }

        public void setEyeballOrigin(Point eyeballOrigin) {
            this.eyeballOrigin = eyeballOrigin;
        }

        public Point getOrigin() {
            return origin;
        }

    }

    public class EyeballListener extends MouseMotionAdapter {

        private final double eyeballDistance = eyeballOuterRadius
                - eyeballInnerRadius - 5;

        @Override
        public void mouseMoved(MouseEvent event) {
            Point p = event.getPoint();
            for (Eye eye : eyes) {
                Point origin = eye.getOrigin();
                double theta = Math.atan2((double) (p.y - origin.y),
                        (double) (p.x - origin.x));
                int x = (int) Math.round(Math.cos(theta) * eyeballDistance)
                        + origin.x;
                int y = (int) Math.round(Math.sin(theta) * eyeballDistance)
                        + origin.y;
                eye.setEyeballOrigin(new Point(x, y));
            }

            drawingPanel.repaint();
        }

    }

}

---

看看这里：您不需要任何ActionListener或计时器。你需要的是一个MouseMotionListener。在其mouseMoved（）方法中，存储鼠标的新坐标，然后调用repaint（）。在paintComponent（）中，使用鼠标坐标计算眼睛应注视的位置。

package com.ggl.testing;

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

public class MovingEyes implements Runnable {

    private static final int drawingWidth = 400;
    private static final int drawingHeight = 400;
    private static final int eyeballHeight = 150;
    private static final int eyeballWidthMargin = 125;
    private static final int eyeballOuterRadius = 50;
    private static final int eyeballInnerRadius = 20;

    private DrawingPanel drawingPanel;

    private Eye[] eyes;

    private JFrame frame;

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

    public MovingEyes() {
        this.eyes = new Eye[2];
        this.eyes[0] = new Eye(new Point(eyeballWidthMargin, eyeballHeight));
        this.eyes[1] = new Eye(new Point(drawingWidth - eyeballWidthMargin,
                eyeballHeight));
    }

    @Override
    public void run() {
        frame = new JFrame("Moving Eyes");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        drawingPanel = new DrawingPanel();
        frame.add(drawingPanel);

        frame.pack();
        frame.setLocationByPlatform(true);
        frame.setVisible(true);
    }

    public class DrawingPanel extends JPanel {

        private static final long serialVersionUID = -2977860217912678180L;

        public DrawingPanel() {
            this.addMouseMotionListener(new EyeballListener());
            this.setBackground(Color.WHITE);
            this.setPreferredSize(new Dimension(drawingWidth, drawingHeight));
        }

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

            g.setColor(Color.BLACK);

            for (Eye eye : eyes) {
                drawCircle(g, eye.getOrigin(), eyeballOuterRadius);
                fillCircle(g, eye.getEyeballOrigin(), eyeballInnerRadius);
            }
        }

        private void drawCircle(Graphics g, Point origin, int radius) {
            g.drawOval(origin.x - radius, origin.y - radius, radius + radius,
                    radius + radius);
        }

        private void fillCircle(Graphics g, Point origin, int radius) {
            g.fillOval(origin.x - radius, origin.y - radius, radius + radius,
                    radius + radius);
        }

    }

    public class Eye {
        private final Point origin;
        private Point eyeballOrigin;

        public Eye(Point origin) {
            this.origin = origin;
            this.eyeballOrigin = origin;
        }

        public Point getEyeballOrigin() {
            return eyeballOrigin;
        }

        public void setEyeballOrigin(Point eyeballOrigin) {
            this.eyeballOrigin = eyeballOrigin;
        }

        public Point getOrigin() {
            return origin;
        }

    }

    public class EyeballListener extends MouseMotionAdapter {

        private final double eyeballDistance = eyeballOuterRadius
                - eyeballInnerRadius - 5;

        @Override
        public void mouseMoved(MouseEvent event) {
            Point p = event.getPoint();
            for (Eye eye : eyes) {
                Point origin = eye.getOrigin();
                double theta = Math.atan2((double) (p.y - origin.y),
                        (double) (p.x - origin.x));
                int x = (int) Math.round(Math.cos(theta) * eyeballDistance)
                        + origin.x;
                int y = (int) Math.round(Math.sin(theta) * eyeballDistance)
                        + origin.y;
                eye.setEyeballOrigin(new Point(x, y));
            }

            drawingPanel.repaint();
        }

    }

}