画圆

package com0326;

import java.awt.FlowLayout;
import java.awt.Graphics;

import javax.swing.JFrame;

import com0326.DrawBorder;
import com0326.DrawListener;

public class DrawBorder extends JFrame{
	//定义主函数
	public static void main(String[] args){
		//实例化DrawBorder类的对象
	DrawBorder db=new DrawBorder();
	//调用initUI函数
	db.initUI();	
	}
	//定义一个initUI函数
	public void initUI(){
		//设置属性值
		this.setTitle("");
		this.setSize(800, 900);
		this.setDefaultCloseOperation(3);
		this.setResizable(true);
		this.setLocationRelativeTo(null);
		this.setLayout(new FlowLayout());
		
	
		this.setVisible(true);
		 
		Graphics g=this.getGraphics();
		DrawListener d=new DrawListener(g);
		this.addMouseListener(d);
		
		
	}
}





package com0326;

import java.awt.Graphics;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;

public class DrawListener implements MouseListener{
    public int x1,x2,y1,y2;
  public int x,y;
   Graphics g;

   public DrawListener(Graphics g){
		this.g=g;
	}
	

	public void mousePressed(MouseEvent e) {
		x1=e.getX();
		y1=e.getY();
	}

	public void mouseReleased(MouseEvent e) {
		System.out.print("ssss");
		x2=e.getX();
		y2=e.getY();
		this.Draw(e);
		}
		
	public void Draw(MouseEvent e){
			for(int i=0;i<50;i++){
				g.drawOval(x1, y1,Math.abs(x1-x2), Math.abs(y1-y2));
				
				x1++;y1++;x2--;y2--;
						
				
			}
	
			
		
		
		
}
		
	
	

	public void mouseEntered(MouseEvent e) {
		
	}

	public void mouseExited(MouseEvent e) {
		
	}
	public void mouseClicked(MouseEvent e) {
		
	}

	

}