draw.java

来自「不错的课件陈述设计一个汇编程序。实现下列功能1.实现加、减、乘、除以及取余的计算」· Java 代码 · 共 35 行

import java.awt.*;
import java.awt.event.*;
import java.applet.*;

public class Draw extends Applet {
  int downx = 0,downy = 0;
  int upx = 0,upy = 0;
  public void init(){
    setBackground(Color.lightGray);
    setForeground(Color.red);
    setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));	
    addMouseListener(new MouseAdapter(){
      public void mousePressed(MouseEvent e){
      	downx = e.getX();
      	downy = e.getY();
      }
      public void mouseReleased(MouseEvent e){
      	upx = e.getX();
      	upy = e.getY();
      	repaint();		
      }
    });
    addMouseMotionListener(new MouseMotionAdapter(){
      public void mouseDragged(MouseEvent e){
      	upx = e.getX();
      	upy = e.getY();
      	repaint();
      }
    });
  }  
  public void paint(Graphics g){  
    g.drawOval(downx,downy,upx-downx,upy-downy);
  }
}