exam11_1.java

java学习课件

/* 绘制曲线程序 Exam11-1.java */
import java.awt.*;
import java.awt.geom.*;
import javax.swing.*;
public class Exam11_1 extends JFrame
{
   public Exam11_1()
   {
     super("Drawing 2D Paint");
     setSize(425,160);
     setVisible(true);
     setDefaultCloseOperation(EXIT_ON_CLOSE);
   }
   public void paint(Graphics g)  //重写绘图方法paint()
   {
     super.paint(g); //调用超类的paint()方法
     float x[]={50,75,100,125,150,175,200,225,250,275};
     float y[]={100,50,100,50,100,50,100,50,100,50};
     GeneralPath curve = new GeneralPath(); //构建GeneralPath类对象
     curve.moveTo(x[0],y[0]);  //将起始点加入路径
     for(int i=1; i<x.length-2;i=i+2)
     curve.curveTo(x[i-1],y[i-1],x[i],y[i],x[i+1],y[i+1]); //将曲线的坐标点加入路径
     Graphics2D g2d = (Graphics2D)g; //强制转换为Graphics2D引用
     g2d.draw(curve);  //绘制曲线
   } //绘图方法结束
   public static void main(String args[])  //主方法main()
   {
     new Exam11_1();
   }    //主方法main()结束
}