没事瞎玩一下

大晚上睡前玩一下，写个小程序。。。哈哈，代码如下：

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics2D;
import java.awt.Toolkit;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

import javax.swing.JFrame;
import javax.swing.JPanel;

/**
 * 画出一颗蒲公英。。。。
 * @author LONG
 *
 */
public class TheTree extends JFrame {
	
	private static final long serialVersionUID = 1L;
	private Dimension di = null;
	private Graphics2D gr = null;
	
	/**
	 * 程序主入口
	 * @param args
	 */
	public static void main(String[] args){
		TheTree tt = new TheTree();
		tt.showFrame();
	}
	public void showFrame(){
		this.setTitle("The Tree");
		Toolkit tl = Toolkit.getDefaultToolkit();
		di = tl.getScreenSize();
		this.setSize(di.width,di.height);
		this.setDefaultCloseOperation(3);
		JPanel jp = new JPanel();
		jp.setPreferredSize(new Dimension(di.width,di.height));
		this.add(jp);
		this.setResizable(false);
		jp.setBackground(Color.BLACK);
		this.setVisible(true);
		gr = (Graphics2D) jp.getGraphics();
		jp.addMouseListener(new MouseAdapter(){
			public void mouseReleased(MouseEvent e){
				draw(e);
			}
		});	
	}
	public void draw(MouseEvent e){
		int x = e.getX();	//自己选择蒲公英生长的位置
		int y = e.getY();
		BasicStroke bs = new BasicStroke(4);
		gr.setStroke(bs);
		gr.setColor(Color.GREEN);
		gr.drawLine(x, y, x, y - 400);	//用来先画出蒲公英的主干
		doSomething(x,y - 400,150);
	}
	
	/**
	 *那我们来画蒲公英吧
	 * 
	 * @param x1	起始点x坐标
	 * @param y1	起始点y坐标
	 * @param h		长度h
	 */
	public void doSomething(int x1, int y1, int h){
		//使循环将所有的蒲公英分支画出来
		for(int i = 0; i < 90; i++){
			double angle = i * 2 * Math.PI/90;		//得到等分的九十个角
			int x2 = x1 + (int)(Math.sin(angle) * h);
			int y2 = y1 - (int)(Math.cos(angle) * h);
			BasicStroke bs_next = new BasicStroke();
			gr.setStroke(bs_next);
			gr.setColor(Color.gray);
			gr.drawLine(x1, y1, x2, y2);
			gr.setColor(Color.WHITE);
			gr.fillOval(x2 - 1, y2 - 1, 5, 5);
		}
	}
}