Java 绘制程序颜色不保留颜色

我真的被卡住了。我似乎不明白为什么我的

paintComponent

以前的颜色一直在改变。我相信问题出在我的

arraylist

，但我不知道如何更改

arraylist

，以便它可以接受不同的颜色

public class Drawing extends JPanel {
    private JRadioButton red, yellow, blue, erase;
    private JButton button;
    private Color c;
    private ArrayList<Point> pointList;
    private int counter = 0;
    private boolean isDrawingMode = true;
    private boolean eraser, isBlue;
    private HashMap test;


    public Drawing() {
        setLayout(new FlowLayout());
        setBackground(Color.white);
        JPanel pane = new JPanel();
        pointList = new ArrayList<Point>();
        addMouseListener(new MouseTrackerListener());

        red = new JRadioButton("Red");
        yellow = new JRadioButton("Yellow");
        blue = new JRadioButton("Blue");
        erase = new JRadioButton("Erase");
        button = new JButton("Clear Drawing");

        red.addActionListener(new ColorActionListener());
        yellow.addActionListener(new ColorActionListener());
        blue.addActionListener(new ColorActionListener());
        erase.addActionListener(new ColorActionListener());
        button.addActionListener(new ColorActionListener());

        pane.add(red);
        pane.add(yellow);
        pane.add(blue);
        pane.add(erase);
        pane.add(button);
        add(pane);
        pane.setBackground(Color.gray);

        ButtonGroup group = new ButtonGroup();
        group.add(red);
        group.add(yellow);
        group.add(blue);
        group.add(erase);

        setPreferredSize(new Dimension(500, 500));
    }

    public void paintComponent(Graphics pen) {
        super.paintComponent(pen);

        pen.setColor(Color.red);
        pen.setColor(c);



        for (int i = 0; i < pointList.size(); i++) {

            Point p = pointList.get(i);

            pen.fillOval(p.x, p.y, 10, 10);

            if (eraser = true) {


                p = pointList.get(i);
                pen.drawOval(p.x, p.y, 10, 10);
            }

        }

    }

    private class MouseTrackerListener extends MouseInputAdapter {
        public void mouseClicked(MouseEvent e) {

            counter++;
            if (counter % 2 != 0) {
                addMouseMotionListener(new MouseTrackerListener());
                isDrawingMode = true;

            } else {
                isDrawingMode = false;
            }

        }

        public void mouseMoved(MouseEvent e) {
            if (isDrawingMode) {
                Point point = e.getPoint();
                pointList.add(point);

                repaint();
            }
        }
    }

    private class ColorActionListener implements ActionListener {
        public void actionPerformed(ActionEvent e) {

            if (e.getSource() == red) {
                c = Color.red;
            } else if (e.getSource() == yellow) {

                c = Color.yellow;

            } else if (e.getSource() == blue) {
                isBlue=true;
                c = Color.blue;
            } else if (e.getSource() == erase) {
                eraser = true;
                c=Color.white;
            } else if (e.getSource() == button) {
                pointList.clear();
                repaint();

            }

        }
    }

    public static void main(String[] args) {
        Drawing draw = new Drawing();
        JFrame frame = new JFrame("Draw Something!");

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().add(draw);
        frame.setSize(450, 450);
        frame.setVisible(true);
    }

}

公共类绘图扩展了JPanel{
私人JRadioButton红色、黄色、蓝色、擦除；
私人按钮；
私有颜色c；
私有ArrayList点列表；
专用整数计数器=0；
私有布尔值isDrawingMode=true；
专用布尔橡皮擦，蓝色；
私有HashMap测试；
公众绘图（）{
setLayout（新的FlowLayout（））；
挫折地面（颜色：白色）；
JPanel窗格=新的JPanel（）；
pointList=新的ArrayList（）；
addMouseListener（新的MouseTrackerListener（））；
红色=新的JRadioButton（“红色”）；
黄色=新的JRadioButton（“黄色”）；
蓝色=新的JRadioButton（“蓝色”）；
擦除=新的JRadioButton（“擦除”）；
按钮=新按钮（“清除图纸”）；
red.addActionListener（新的ColorActionListener（））；
黄色.addActionListener（新的ColorActionListener（））；
blue.addActionListener（新的ColorActionListener（））；
erase.addActionListener（新的ColorActionListener（））；
addActionListener（新的ColorActionListener（））；
窗格。添加（红色）；
窗格。添加（黄色）；
窗格。添加（蓝色）；
窗格。添加（删除）；
窗格。添加（按钮）；
添加（窗格）；
窗格。背景（颜色。灰色）；
ButtonGroup=新建ButtonGroup（）；
组。添加（红色）；
添加组（黄色）；
添加组（蓝色）；
组。添加（删除）；
setPreferredSize（新尺寸（500500））；
}
公共组件（图形笔）{
超级油漆组件（pen）；
钢笔颜色（颜色：红色）；
pen.setColor（c）；
对于（int i=0；i

创建一个自定义类，该类可以包含有关要绘制的内容以及如何绘制的信息（颜色和形状）

使用此选项，而不是存储

点

public void mouseMoved(MouseEvent e) {
    if (isDrawingMode) {
        Point point = e.getPoint();
        pointList.add(new Dot(point, c));

        repaint();
    }
}

（您需要更新

点列表

以接受

点

，而不是

点

）

然后简单地画你的“点”

@覆盖
受保护的组件（图形笔）{
超级油漆组件（pen）；
对于（int i=0；i

示例

import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.HashMap;
import javax.swing.ButtonGroup;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.event.MouseInputAdapter;

public class Drawing extends JPanel {

    private JRadioButton red, yellow, blue, erase;
    private JButton button;
    private Color c;
    private ArrayList<Dot> pointList;
    private int counter = 0;
    private boolean isDrawingMode = true;
    private boolean eraser, isBlue;
    private HashMap test;

    public Drawing() {
        setLayout(new FlowLayout());
        setBackground(Color.white);
        JPanel pane = new JPanel();
        pointList = new ArrayList<Dot>();
        addMouseListener(new MouseTrackerListener());

        red = new JRadioButton("Red");
        yellow = new JRadioButton("Yellow");
        blue = new JRadioButton("Blue");
        erase = new JRadioButton("Erase");
        button = new JButton("Clear Drawing");

        red.addActionListener(new ColorActionListener());
        yellow.addActionListener(new ColorActionListener());
        blue.addActionListener(new ColorActionListener());
        erase.addActionListener(new ColorActionListener());
        button.addActionListener(new ColorActionListener());

        pane.add(red);
        pane.add(yellow);
        pane.add(blue);
        pane.add(erase);
        pane.add(button);
        add(pane);
        pane.setBackground(Color.gray);

        ButtonGroup group = new ButtonGroup();
        group.add(red);
        group.add(yellow);
        group.add(blue);
        group.add(erase);

        setPreferredSize(new Dimension(500, 500));
    }

    public void paintComponent(Graphics pen) {
        super.paintComponent(pen);
        for (int i = 0; i < pointList.size(); i++) {

            Dot p = pointList.get(i);
            p.draw(pen);

        }

    }

    private class MouseTrackerListener extends MouseInputAdapter {

        public void mouseClicked(MouseEvent e) {

            counter++;
            if (counter % 2 != 0) {
                addMouseMotionListener(new MouseTrackerListener());
                isDrawingMode = true;

            } else {
                isDrawingMode = false;
            }

        }

    public void mouseMoved(MouseEvent e) {
        if (isDrawingMode) {
            Point point = e.getPoint();
            pointList.add(new Dot(point, c));

            repaint();
        }
    }
    }

    private class ColorActionListener implements ActionListener {

        public void actionPerformed(ActionEvent e) {

            if (e.getSource() == red) {
                c = Color.red;
            } else if (e.getSource() == yellow) {
                c = Color.yellow;
            } else if (e.getSource() == blue) {
                c = Color.blue;
            } else if (e.getSource() == erase) {
                eraser = true;
                c = Color.white;
            } else if (e.getSource() == button) {
                pointList.clear();
            }
            repaint();

        }
    }

    public class Dot {

        private Point p;
        private Color color;

        public Dot(Point p, Color color) {
            this.p = p;
            this.color = color;
        }

        public void draw(Graphics g) {
            g.setColor(color);
            g.drawOval(p.x, p.y, 10, 10);
        }

    }

    public static void main(String[] args) {
        Drawing draw = new Drawing();
        JFrame frame = new JFrame("Draw Something!");

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().add(draw);
        frame.setSize(450, 450);
        frame.setVisible(true);
    }
}

导入java.awt.Color；
导入java.awt.Dimension；
导入java.awt.FlowLayout；
导入java.awt.Graphics；
导入java.awt.Point；
导入java.awt.event.ActionEvent；
导入java.awt.event.ActionListener；
导入java.awt.event.MouseEvent；
导入java.util.ArrayList；
导入java.util.HashMap；
导入javax.swing.ButtonGroup；
导入javax.swing.JButton；
导入javax.swing.JFrame；
导入javax.swing.JPanel；
导入javax.swing.JRadioButton；
导入javax.swing.event.MouseInputAdapter；
公共类绘图扩展了JPanel{
私人JRadioButton红色、黄色、蓝色、擦除；
私人按钮；
私有颜色c；
私有ArrayList点列表；
专用整数计数器=0；
私有布尔值isDrawingMode=true；
专用布尔橡皮擦，蓝色；
私有HashMap测试；
公众绘图（）{
setLayout（新的FlowLayout（））；
挫折地面（颜色：白色）；
JPanel窗格=新的JPanel（）；
pointList=新的ArrayList（）；
addMouseListener（新的MouseTrackerListener（））；
红色=新的JRadioButton（“红色”）；
黄色=新的JRadioButton（“黄色”）；
蓝色=新的JRadioButton（“蓝色”）；
擦除=新的JRadioButton（“擦除”）；
按钮=新按钮（“清除图纸”）；
red.addActionListener（新的ColorActionListener（））；
黄色.addActionListener（新的ColorActionListener（））；
blue.addActionListener（新的ColorActionListener（））；
erase.addActionListener（新的ColorActionListener（））；
addActionListener（新的ColorActionListener（））；
窗格。添加（红色）；
窗格。添加（黄色）；
窗格。添加（蓝色）；
窗格。添加（删除）；
窗格。添加（按钮）；
添加（窗格）；
@Override
protected void paintComponent(Graphics pen) {
    super.paintComponent(pen);
    for (int i = 0; i < pointList.size(); i++) {

        Dot p = pointList.get(i);
        p.draw(pen);

    }
}

import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.HashMap;
import javax.swing.ButtonGroup;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.event.MouseInputAdapter;

public class Drawing extends JPanel {

    private JRadioButton red, yellow, blue, erase;
    private JButton button;
    private Color c;
    private ArrayList<Dot> pointList;
    private int counter = 0;
    private boolean isDrawingMode = true;
    private boolean eraser, isBlue;
    private HashMap test;

    public Drawing() {
        setLayout(new FlowLayout());
        setBackground(Color.white);
        JPanel pane = new JPanel();
        pointList = new ArrayList<Dot>();
        addMouseListener(new MouseTrackerListener());

        red = new JRadioButton("Red");
        yellow = new JRadioButton("Yellow");
        blue = new JRadioButton("Blue");
        erase = new JRadioButton("Erase");
        button = new JButton("Clear Drawing");

        red.addActionListener(new ColorActionListener());
        yellow.addActionListener(new ColorActionListener());
        blue.addActionListener(new ColorActionListener());
        erase.addActionListener(new ColorActionListener());
        button.addActionListener(new ColorActionListener());

        pane.add(red);
        pane.add(yellow);
        pane.add(blue);
        pane.add(erase);
        pane.add(button);
        add(pane);
        pane.setBackground(Color.gray);

        ButtonGroup group = new ButtonGroup();
        group.add(red);
        group.add(yellow);
        group.add(blue);
        group.add(erase);

        setPreferredSize(new Dimension(500, 500));
    }

    public void paintComponent(Graphics pen) {
        super.paintComponent(pen);
        for (int i = 0; i < pointList.size(); i++) {

            Dot p = pointList.get(i);
            p.draw(pen);

        }

    }

    private class MouseTrackerListener extends MouseInputAdapter {

        public void mouseClicked(MouseEvent e) {

            counter++;
            if (counter % 2 != 0) {
                addMouseMotionListener(new MouseTrackerListener());
                isDrawingMode = true;

            } else {
                isDrawingMode = false;
            }

        }

    public void mouseMoved(MouseEvent e) {
        if (isDrawingMode) {
            Point point = e.getPoint();
            pointList.add(new Dot(point, c));

            repaint();
        }
    }
    }

    private class ColorActionListener implements ActionListener {

        public void actionPerformed(ActionEvent e) {

            if (e.getSource() == red) {
                c = Color.red;
            } else if (e.getSource() == yellow) {
                c = Color.yellow;
            } else if (e.getSource() == blue) {
                c = Color.blue;
            } else if (e.getSource() == erase) {
                eraser = true;
                c = Color.white;
            } else if (e.getSource() == button) {
                pointList.clear();
            }
            repaint();

        }
    }

    public class Dot {

        private Point p;
        private Color color;

        public Dot(Point p, Color color) {
            this.p = p;
            this.color = color;
        }

        public void draw(Graphics g) {
            g.setColor(color);
            g.drawOval(p.x, p.y, 10, 10);
        }

    }

    public static void main(String[] args) {
        Drawing draw = new Drawing();
        JFrame frame = new JFrame("Draw Something!");

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().add(draw);
        frame.setSize(450, 450);
        frame.setVisible(true);
    }
}