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java如何打圆形

2026-03-21 06:57:58Java

使用Graphics2D绘制圆形

在Java中，可以通过Graphics2D类绘制圆形。Graphics2D提供了drawOval和fillOval方法，分别用于绘制空心圆形和实心圆形。以下是示例代码：

import javax.swing.*;
import java.awt.*;

public class DrawCircle extends JPanel {
    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2d = (Graphics2D) g;

        // 绘制空心圆形
        g2d.drawOval(50, 50, 100, 100);

        // 绘制实心圆形
        g2d.setColor(Color.RED);
        g2d.fillOval(200, 50, 100, 100);
    }

    public static void main(String[] args) {
        JFrame frame = new JFrame("绘制圆形");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(new DrawCircle());
        frame.setSize(400, 200);
        frame.setVisible(true);
    }
}

使用JavaFX绘制圆形

JavaFX提供了Circle类，可以更方便地绘制圆形。以下是示例代码：

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.stage.Stage;

public class DrawCircleFX extends Application {
    @Override
    public void start(Stage primaryStage) {
        Pane pane = new Pane();

        // 绘制空心圆形
        Circle circle1 = new Circle(100, 100, 50);
        circle1.setFill(null);
        circle1.setStroke(Color.BLUE);
        circle1.setStrokeWidth(2);

        // 绘制实心圆形
        Circle circle2 = new Circle(200, 100, 50);
        circle2.setFill(Color.RED);

        pane.getChildren().addAll(circle1, circle2);

        Scene scene = new Scene(pane, 300, 200);
        primaryStage.setTitle("绘制圆形");
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    public static void main(String[] args) {
        launch(args);
    }
}

使用AWT绘制圆形

如果只需要简单的图形绘制，可以使用AWT的Graphics类：

import java.awt.*;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

public class DrawCircleAWT extends Frame {
    public DrawCircleAWT() {
        setSize(300, 200);
        addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
    }

    public void paint(Graphics g) {
        // 绘制空心圆形
        g.drawOval(50, 50, 100, 100);

        // 绘制实心圆形
        g.setColor(Color.RED);
        g.fillOval(200, 50, 100, 100);
    }

    public static void main(String[] args) {
        DrawCircleAWT frame = new DrawCircleAWT();
        frame.setVisible(true);
    }
}