Java实现的简单画图板示例

package awtDemo;import java.awt.BorderLayout;import java.awt.Color;import java.awt.Dimension;import java.awt.FlowLayout;import javax.swing.JButton;import javax.swing.JFrame;import javax.swing.JPanel;@SuppressWarnings("serial")public class DrawMain extends JPanel {    public static void main(String[] args) {        // TODO Auto-generated method stub        DrawMain Draw = new DrawMain();        Draw.InitUI();    }    public void InitUI() {        JFrame jf = new JFrame();        jf.setSize(1000, 780);        jf.setTitle("简单画板");        jf.setDefaultCloseOperation(3);        jf.setLocationRelativeTo(null);        jf.setLayout(new BorderLayout());        // 实例化事件监听类        DrawListener dl = new DrawListener(this);        // 实现中间面板        this.setBackground(Color.WHITE);        jf.add(this, BorderLayout.CENTER);        // 实现性状面板        JPanel ShapePanel = new JPanel();        ShapePanel.setBackground(Color.black);        ShapePanel.setLayout(new FlowLayout(FlowLayout.CENTER));        ShapePanel.setBackground(Color.gray);        ;        String[] Shape = { "直线", "曲线", "圆", "喷枪", "橡皮擦", "矩形", "椭圆", "圆角矩形",                "弧线", "多边形", "图形", "三角形", "立体圆", };        for (int i = 0; i < Shape.length; i++) {            JButton button = new JButton(Shape[i]);            button.setBackground(Color.WHITE);            button.addActionListener(dl); // 添加事件监听机制            ShapePanel.add(button);        }        jf.add(ShapePanel, BorderLayout.NORTH);        // 实现颜色面板        JPanel ColorPanel = new JPanel();        ColorPanel.setBackground(Color.black);        ColorPanel.setLayout(new FlowLayout(FlowLayout.CENTER));        ColorPanel.setBackground(Color.gray);        ;        Color[] color = { Color.BLACK, Color.blue, Color.white, Color.gray,                Color.red, Color.CYAN, Color.green, Color.darkGray, Color.pink };        for (int i = 0; i < color.length; i++) {            JButton button = new JButton();            button.addActionListener(dl); // 添加事件监听机制            button.setPreferredSize(new Dimension(30, 30));            button.setBackground(color[i]);            ColorPanel.add(button);        }        jf.add(ColorPanel, BorderLayout.SOUTH);        jf.setVisible(true);        this.addMouseListener(dl);        this.addMouseMotionListener(dl);    }}

package awtDemo;import java.awt.BasicStroke;import java.awt.Color;import java.awt.Graphics2D;import java.awt.RenderingHints;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.awt.event.MouseAdapter;import java.awt.event.MouseEvent;import java.util.Random;import javax.swing.JButton;public class DrawListener extends MouseAdapter implements ActionListener {    private int x1, y1, x2, y2;    private int newx1, newy1, newx2, newy2;    private Graphics2D g;    private DrawMain df;    private boolean flag = false;    String shape = "直线";    Color color;    private int[] arrx = new int[4];    private int[] arry = new int[4];    private int temp = 0;    DrawListener(DrawMain d) {        df = d;    }    // 获取形状和颜色    public void actionPerformed(ActionEvent e) {        if (e.getActionCommand().equals("")) {            JButton button = (JButton) e.getSource();            color = button.getBackground();            System.out.println("color = " + color);        } else {            JButton button = (JButton) e.getSource();            shape = button.getActionCommand();            System.out.println("String = " + shape);        }    }    // 实现画笔    public void mousePressed(MouseEvent e) {        g = (Graphics2D) df.getGraphics();        g.setColor(color);        x1 = e.getX();        y1 = e.getY();    }    public void mouseReleased(MouseEvent e) {        x2 = e.getX();        y2 = e.getY();        if (shape.equals("直线")) {            g.drawLine(x1, y1, x2, y2);        } else if (shape.equals("弧线")) {            g.drawArc(x1, y1, Math.abs(x2 - x1), Math.abs(y2 - y1), 0, 180);        } else if (shape.equals("多边形") && !flag) {            g.drawLine(x1, y1, x2, y2);            newx1 = x1;            newy1 = y1;            newx2 = x2;            newy2 = y2;            flag = true;        } else if (shape.equals("圆")) {            g.drawOval(x1, y1, Math.abs(x2 - x1), Math.abs(y2 - y1));        } else if (shape.equals("矩形")) {            g.drawRect(x1, y1, Math.abs(x2 - x1), Math.abs(y2 - y1));        } else if (shape.equals("圆角矩形")) {            g.drawRoundRect(x1, y1, Math.abs(x2 - x1), Math.abs(y2 - y1), 2, 10);        } else if (shape.equals("椭圆")) {            g.drawOval(x1, y1, Math.abs(x2 - x1), Math.abs(y2 - y1));        }    }    public void mouseClicked(MouseEvent e) {        if (shape.equals("多边形") && flag) {            x2 = e.getX();            y2 = e.getY();            if (e.getClickCount() == 2) {                g.drawLine(newx1, newy1, newx2, newy2);                flag = false;            }            g.drawLine(newx2, newy2, x2, y2);            newx2 = x2;            newy2 = y2;        } else if (shape.equals("图形")) {            arrx[temp] = e.getX();            arry[temp] = e.getY();            temp++;            if (temp == 4) {                int x = arrx[3];                int y = arry[3];                for (int i = 0; i <= 10000; i++) {                    Random ran = new Random();                    int k = ran.nextInt(3);                    x = (x + arrx[k]) / 2;                    y = (y + arry[k]) / 2;                    g.drawLine(x, y, x, y);                }                temp = 0;            }        } else if (shape.equals("立体圆")) {            // double a=-2,b=-2,c=-1.2,d=2;            double a = 1.40, b = 1.56, c = 1.40, d = -6.56;            double x = 0, xo = 0;            double y = 0, yo = 0;            Color[] Col = { Color.BLUE, Color.cyan, Color.green, Color.magenta,                    Color.red, Color.yellow };            for (int i = 0; i <= 90000; i++) {                Random r = new Random(); // 增加颜色                int R = r.nextInt(Col.length);                g.setColor(Col[R]);                // x=Math.sin(a*yo)-Math.cos(b*xo);                // y=Math.sin(c*xo)-Math.cos(d*yo);                x = d * Math.sin(a * xo) - Math.sin(b * yo);                y = c * Math.cos(a * xo) + Math.cos(b * yo);                int temp_x = (int) (x * 50);                int temp_y = (int) (y * 50);                g.drawLine(temp_x + 500, temp_y + 300, temp_x + 500,                        temp_y + 300);                xo = x;                yo = y;            }        } else if (shape.equals("三角形")) {            double a = -2, b = -2, c = -1.2, d = 2;            double x = 0, xo = 0;            double y = 0, yo = 0;            Color[] Col = { Color.BLUE, Color.cyan, Color.green, Color.magenta,                    Color.red, Color.yellow };            for (int i = 0; i <= 90000; i++) {                Random r = new Random(); // 增加颜色                int R = r.nextInt(Col.length);                g.setColor(Col[R]);                x = Math.sin(a * yo) - Math.cos(b * xo);                y = Math.sin(c * xo) - Math.cos(d * yo);                int temp_x = (int) (x * 50);                int temp_y = (int) (y * 50);                g.drawLine(temp_x + 500, temp_y + 300, temp_x + 500,                        temp_y + 300);                xo = x;                yo = y;            }        }    }    public void mouseDragged(MouseEvent e) {        x2 = e.getX();        y2 = e.getY();        if (shape.equals("曲线")) {            // g.setStroke(new BasicStroke(10));            // g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,            // RenderingHints.VALUE_ANTIALIAS_ON);            g.drawLine(x1, y1, x2, y2);            x1 = x2;            y1 = y2;        } else if (shape.equals("橡皮擦")) {            g.setStroke(new BasicStroke(80));            g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,                    RenderingHints.VALUE_ANTIALIAS_ON);            g.setColor(Color.WHITE);            g.drawLine(x1, y1, x2, y2);            x1 = x2;            y1 = y2;        } else if (shape.equals("喷枪")) {            // g.setStroke(new BasicStroke(2)); //不用加粗            // g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,            // RenderingHints.VALUE_ANTIALIAS_ON);            for (int k = 0; k < 20; k++) {                Random i = new Random();                int a = i.nextInt(8);                int b = i.nextInt(10);                g.drawLine(x2 + a, y2 + b, x2 + a, y2 + b);            }        }    }}