suanshu.java

课堂上的练习题,简单的乘除运算,适合新手学习

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import javax.swing.border.*;
public class suanshu  implements ActionListener
{
	JFrame f;
	JPanel p1,p2,p3,p4;
	JLabel l1,l2;
	JButton b1,b2,b3;
	JTextField t1,t2,l;
	public static JLabel lm;
	
	
	double cc=0;
	public static void main(String args[])
	{
		suanshu s=new suanshu();
		lm=s.go();
		
	
	
	  
	
	
    }
    JLabel go()
    {
       f=new JFrame("算术运算");
       p1=new JPanel();
       p2=new JPanel();	
       p3=new JPanel();	
       p4=new JPanel();	
       lm=new JLabel();
       l1=new JLabel("第一个数:");
       l2=new JLabel("第二个数:");
       l=new JTextField(38);
       t1=new JTextField(30);
       t2=new JTextField(30);
       b1=new JButton("乘",new ImageIcon("cheng.gif"));	
       b2=new JButton("除",new ImageIcon("chu.gif"));	
       b3=new JButton("清除",new ImageIcon("qingchu.gif"));
       Border etched=BorderFactory.createEtchedBorder();
		Border border=BorderFactory.createTitledBorder(etched,"乘除运算");
		p1.setBorder(border);
        f.add(p1,BorderLayout.CENTER);
       f.add(l,BorderLayout.SOUTH);
    	
       p1.add(p2);
       p1.add(p3);
       p1.add(b1);p1.add(b2);p1.add(b3);
       p2.add(l1);p2.add(l2);p1.add(lm);
       p3.add(t1);p3.add(t2);
       p1.setLayout(new FlowLayout());
       p2.setLayout(new BoxLayout(p2,BoxLayout.Y_AXIS));
       p3.setLayout(new BoxLayout(p3,BoxLayout.Y_AXIS));
       f.setSize(500,300);
       f.setVisible(true);
    	b1.addActionListener(this);b2.addActionListener(this);b3.addActionListener(this);
    
    	return lm;
    }
    public void actionPerformed(ActionEvent e)
    {
    	String s1=t1.getText();
    	String s2=t2.getText();
        double d1=Double.parseDouble(s1);
        double d2=Double.parseDouble(s2);
        long start = System.currentTimeMillis();
        if(e.getSource()==b1)
        {
        	cc=d1*d2;l.setText("结果为"+cc);
        } else if(e.getSource()==b2)
        {
        	if(d2==0.0)
        	l.setText("除数不能为零"); 
        	else
        	{
        		cc=d1/d2;l.setText("结果为"+cc);
        	}
        } else if(e.getSource()==b3)
        {
        	l.setText("");t1.setText("");t2.setText("");
        }
        long time = System.currentTimeMillis() - start;
        System.out.println(time);
        lm.setText("计算消耗时间为"+String.valueOf(time));
    }
    

    
}