simpledraw.java

《JAVA程序设计教程》源代码

//SimpleDraw

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

public class SimpleDraw
{
	public static void main(String[] args)
	{
		DrawFrame frame = new DrawFrame();
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.show();  
	}
}

class DrawFrame extends JFrame
{
	public DrawFrame()
	{
		setTitle("简单图形绘制");
		setSize(WIDTH, HEIGHT);
		
		// 将panel加入到frame
		DrawPanel panel = new DrawPanel();
		Container contentPane = getContentPane();
		contentPane.add(panel);
	}
	
	public static final int WIDTH = 300;
	public static final int HEIGHT = 200;  	
}

class DrawPanel extends JPanel
{ 
	public void paintComponent(Graphics g)
	{ 
		super.paintComponent(g);
		
		int x1 = 50;
		int y1 = 50;
		int x2 = 50;
		int y2 = 150;
		int radius = 100;		//半径
		int startAngle = - 90;	//起始角度
		int arcAngle = 180;		//弧的角度
		
		//画线
		g.drawLine(x1, y1, x2, y2);

		//画弧
		g.drawArc(x1 - radius / 2 , y1 , 
			radius, radius, startAngle, arcAngle);
		
		Polygon p = new Polygon();
		x1 += 150;
		y1 += 50;
		radius /= 2;
		int i;
		for (i = 0; i < 6; i++)
			p.addPoint(
			(int)(x1 + radius * Math.cos(i * 2 * Math.PI / 6)),
			(int)(y1 + radius * Math.sin(i * 2 * Math.PI / 6)));
		
		//画六边形
		g.drawPolygon(p);      
   }
}