如何在Java中制作四色圆圈

Question

How to Make Circle with Four Color in Java?

My way stuck until this step.

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;

public class CircleDraw extends Frame {
  Shape circle = new Ellipse2D.Float(100.0f, 100.0f, 100.0f, 100.0f);
  Shape square = new Rectangle2D.Double(100, 100,100, 100);
  public void paint(Graphics g) {
  Graphics2D ga = (Graphics2D)g;
  ga.draw(circle);
  ga.setPaint(Color.green);
  ga.fill(circle);
  ga.setPaint(Color.red);
  ga.draw(square);
  }

  public static void main(String args[]) {
  Frame frame = new CircleDraw();
  frame.addWindowListener(new WindowAdapter(){
  public void windowClosing(WindowEvent we){
  System.exit(0);
  }
  });
  frame.setSize(300, 250);
  frame.setVisible(true);
  }
}

Answer 1

You can use java.awt.geom.Arc2D to draw slices of the Circle

see below code ,

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;

public class CircleDraw extends Frame {

    public void paint(Graphics g) {
        Graphics2D ga = (Graphics2D) g;

        ga.setPaint(Color.YELLOW);
        Arc2D arc2D4 = new Arc2D.Double(100.0f, 100.0f, 100.0f, 100.0f, 90, 270, Arc2D.PIE);
        ga.fill(arc2D4);
        ga.draw(arc2D4);

        ga.setPaint(Color.GREEN);
        Arc2D arc2D1 = new Arc2D.Double(100.0f, 100.0f, 100.0f, 100.0f, 90, 90d, Arc2D.PIE);
        ga.fill(arc2D1);
        ga.draw(arc2D1);

        ga.setPaint(Color.RED);
        Arc2D arc2D2 = new Arc2D.Double(100.0f, 100.0f, 100.0f, 100.0f, 360, 90d, Arc2D.PIE);
        ga.fill(arc2D2);
        ga.draw(arc2D2);

        ga.setPaint(Color.BLUE);
        Arc2D arc2D3 = new Arc2D.Double(100.0f, 100.0f, 100.0f, 100.0f, 180, 90d, Arc2D.PIE);
        ga.fill(arc2D3);
        ga.draw(arc2D3);

    }

    public static void main(String args[]) {
        Frame frame = new CircleDraw();
        frame.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent we) {
                System.exit(0);
            }
        });
        frame.setSize(300, 250);
        frame.setVisible(true);
    }
}

out put will look like this !