看到网上经常有人寻找简单计算器的源代码，于是今天花了点时间写了一个简单的计算器，供大家参考一下.

 

import javax.swing.*;
import javax.swing.event.*;
import java.awt.*;
import java.awt.event.*;
public class Jsq extends JFrame
{
 double a=0,b=0,c=0;
 int i=0;
 JPanel pl1=new JPanel();
 JPanel pl2=new JPanel();
 JTextField tf=new JTextField(10);
 JButton bt=new JButton("清空");
    JButton bt1=new JButton("1");
    JButton bt2=new JButton("2");
    JButton bt3=new JButton("3");
    JButton bt4=new JButton("4");
    JButton bt5=new JButton("5");
    JButton bt6=new JButton("6");
    JButton bt7=new JButton("7");
    JButton bt8=new JButton("8");
    JButton bt9=new JButton("9");
    JButton bt10=new JButton("0");
    JButton bt11=new JButton("+");
    JButton bt12=new JButton("-");
    JButton bt13=new JButton("*");
    JButton bt14=new JButton("/");
    JButton bt15=new JButton(".");
    JButton bt16=new JButton("=");
 
 public Jsq()
 {
  super("计算器");
  Container c=getContentPane();
  c.add(pl1,BorderLayout.NORTH);
  c.add(pl2,BorderLayout.CENTER);
  pl1.setLayout(new FlowLayout());
  pl1.add(tf);
  pl1.add(bt);
  
  pl2.setLayout(new GridLayout(4,4));
  pl2.add(bt1);
     pl2.add(bt2);
     pl2.add(bt3);
     pl2.add(bt11);
     pl2.add(bt4);
     pl2.add(bt5);
     pl2.add(bt6);
     pl2.add(bt12);
     pl2.add(bt7);
     pl2.add(bt8);
     pl2.add(bt9);
     pl2.add(bt13);
     pl2.add(bt10);
     pl2.add(bt14);
     pl2.add(bt15);
     pl2.add(bt16);
    
     bt.addActionListener(new shijian());
     bt1.addActionListener(new shijian());
     bt2.addActionListener(new shijian());
     bt3.addActionListener(new shijian());
     bt4.addActionListener(new shijian());
     bt5.addActionListener(new shijian());
     bt6.addActionListener(new shijian());
     bt7.addActionListener(new shijian());
     bt8.addActionListener(new shijian());
     bt9.addActionListener(new shijian());
     bt10.addActionListener(new shijian());
     bt11.addActionListener(new shijian());
     bt12.addActionListener(new shijian());
     bt13.addActionListener(new shijian());
     bt14.addActionListener(new shijian());
     bt15.addActionListener(new shijian());
     bt16.addActionListener(new shijian());
  
  setSize(200,200);
  setVisible(true);
  setResizable(false);
  setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  
     }
     public static void main(String args[])
     {
      new Jsq();
     }
    
 class shijian implements ActionListener
 {
  public void actionPerformed(ActionEvent e)
  {
   if(e.ge