abstractarea.java

来自「精通Java核心技术源代码」· Java 代码 · 共 27 行

import javax.swing.*;
import java.awt.*;
	
	class AbstractArea extends JFrame
	{
	 	public AbstractArea()
	 	{
    	 	super("abstract class");
		 	setSize(400,400);
		  	show();
			
	 	}
	 	public void paint(Graphics g)
	 	{
	 		Rectangle  rect=new Rectangle(10.0,10.0);
	 		Triangle   tri=new  Triangle(10.0,10.0);
	 		g.drawString("矩形的长是10.0 宽是10.0",90,100);
	 		g.drawString("其面积是"+rect.area()+"。",90,120);
	 		g.drawString("三角形的长是10.0 高是10.0",90,200);
	 		g.drawString("其面积是"+tri.area()+"。",90,220);  	
	 	}
	 	public static void main(String  args[])
	 	{
	 		AbstractArea abarea=new AbstractArea();	   	 
	 	}   
	}