简介

java 2D绘图

code

/*
 * @Author: your name
 * @Date: 2020-10-28 21:36:29
 * @LastEditTime: 2020-10-28 21:51:30
 * @LastEditors: Please set LastEditors
 * @Description: In User Settings Edit
 * @FilePath: /java/DrawTest.java
 */
import java.awt.*;
import java.awt.geom.*;
import javax.swing.*;

public class DrawTest {
    public static void main(String[] args) {
        EventQueue.invokeLater(() -> {
            JFrame frame = new DrawFrame();
            frame.setTitle("DrawTest");
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            frame.setVisible(true);
        });
    }
}

class DrawFrame extends JFrame {
    public DrawFrame() {
        add(new DrawComponent());
        pack();
    }
}

class DrawComponent extends JComponent {
    private static final int DEFAULT_WIDTH = 400;
    private static final int DEFAULT_HEIGHT = 400;

    public void paintComponent(Graphics g) {
        Graphics2D g2 = (Graphics2D) g;
        // draw a rectangle
        double leftX = 100;
        double topY = 100;
        double width = 200;
        double height = 150;
        Rectangle2D rect = new Rectangle2D.Double(leftX, topY, width, height);
        g2.draw(rect);

        // draw the enclosed ellipse

        Ellipse2D ellipse = new Ellipse2D.Double();
        ellipse.setFrame(rect);
        g2.draw(ellipse);

        // draw a diagonal line

        g2.draw(new Line2D.Double(leftX, topY, leftX + width, topY + height)); 

        // draw a circle with the same center

        double centerX = rect.getCenterX();
        double centerY = rect.getCenterY();
        double radius = 150;

        Ellipse2D circle = new Ellipse2D.Double();
        circle.setFrameFromCenter(centerX, centerY, centerX + radius, centerY + radius);
        g2.draw(circle);
    }

    public Dimension getPreferredSize() {
        return new Dimension(DEFAULT_WIDTH, DEFAULT_HEIGHT);
    }
}

result

image