userelation.java

用java语言编写的计算程序

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

/*
	Example 3-5
*/
public class UseRelation extends Applet implements ActionListener
{
	Label prompt;
	TextField in1,in2;
	Button btn;
	int a=0,b=1;
	//boolean a=true,b=false;
	
	public void init()
	{
		prompt = new Label("请输入两个整型数据:");
		in1 = new TextField(5);
		in2 = new TextField(5);
		btn = new Button("计算");
		add(prompt);
		add(in1);
		add(in2);
		add(btn);
		btn.addActionListener(this);
	}
	
	public void actionPerformed(ActionEvent e)
	{
		//a = Boolean.valueOf(in1.getText()).booleanValue();
		//b = Boolean.valueOf(in2.getText()).booleanValue();
		a = Integer.parseInt(in1.getText());
		b = Integer.parseInt(in2.getText());
		repaint();
	}
	
	public void paint(Graphics g)
	{
		g.drawString(a+">"+b+"="+(a>b),10,50);
		g.drawString(a+"<"+b+"="+(a<b),10,70);
		g.drawString(a+">="+b+"="+(a>=b),10,90);
		g.drawString(a+"<="+b+"="+(a<=b),10,110);
		g.drawString(a+"=="+b+"="+(a==b),10,130);
		g.drawString(a+"!="+b+"="+(a!=b),10,150);
	}
	
}