drawpanel.java

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package drawr_e;

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

/**
 * <p>Title: Draw_Fill_Rectangle_Ellipse</p>
 * <p>Description: 应用Java 2D API绘制矩形和椭圆以及填充颜色</p>
 * <p>Copyright: Copyright (c) 2004</p>
 * <p>Company: 北京师范大学计算机系</p>
 * @author 张良博
 * @version 1.0
 */

public class DrawPanel extends JPanel {
  public void paintComponent(Graphics g){
    super.paintComponent(g);
    Graphics2D g2 = (Graphics2D)g;
    double leftX = 50;         // 绘制矩形
    double topY = 30;
    double width = 200;
    double height = 150;
    Rectangle2D rect = new Rectangle2D.Double(leftX, topY, width, height);//使用给定的左上角坐标、宽度和高度构造一个矩形
    g2.draw(rect);
//    g2.setPaint(Color.yellow);//将矩形填充成黄色
//    g2.fill(rect);

    // 绘制内接椭圆
    double centerX = rect.getCenterX();
    double centerY = rect.getCenterY();
    Ellipse2D ellipse = new Ellipse2D.Double();//根据给定边界矩形的左上角、宽度和高度构造一个椭圆
    ellipse.setFrame(rect);
    g2.draw(ellipse);
//    g2.setPaint(new Color(0,  128, 128)); // 兰绿色
//    g2.fill(ellipse);

  }
}