frame1.java

jbuilder2005

package quadcurvetest;

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

public class Frame1
    extends JFrame {
  JPanel contentPane;
  BorderLayout borderLayout1 = new BorderLayout();

  public Frame1() {
    try {
      setDefaultCloseOperation(EXIT_ON_CLOSE);
      jbInit();
    }
    catch (Exception exception) {
      exception.printStackTrace();
    }
  }

  /**
   * Component initialization.
   *
   * @throws java.lang.Exception
   */
  private void jbInit() throws Exception {
    contentPane = (JPanel) getContentPane();
    contentPane.setLayout(borderLayout1);
    setSize(new Dimension(300, 200));
    setTitle("绘制二次曲线");
  }
  public void paint(Graphics g){
    Graphics2D g2d = (Graphics2D) g; //Graphics2D对象由Graphics对象转换而来。
    g.setColor(Color.blue);
    QuadCurve2D c1 = new QuadCurve2D.Double(50, 50, 10, 100, 50, 150);
    g2d.draw(c1);
    g.setColor(Color.red);
    QuadCurve2D c2 = new QuadCurve2D.Double(50, 50, 280, 100, 50, 150);
    //两条曲线的端点重合，都是(50,50)和(50,150)
    g2d.draw(c2);
  }

}