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 

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);
            }
        }
    }
}