java的小学生四则运算

import java.awt.*;

import java.awt.event.*;

import java.io.FileNotFoundException;

import java.io.IOException;

import javax.swing.*;

public class Login extends JFrame  {

    private TextField f1;

    private TextField f2;

    private JButton b1;

    private JButton b2;

    private JButton b3;

    Yunsuan scs=new Yunsuan();

    //登陆界面

    public Login(){

        Container cp=getContentPane();//容器

        cp.setLayout(new GridLayout(3,1));//三行一列布局

        Label l1=new Label("用户名");

        Label l2=new Label("密   码");

        Panel p1=new Panel();

        Panel p2=new Panel();

        Panel p3=new Panel();

        f1=new TextField(10);

        f2=new TextField(10);

        f2.setEchoChar('*');//回显字符为*

        b1=new JButton("登录");

        b2=new JButton("重置");

        b3=new JButton("退出");

        p1.add(l1);//第一行添加label 1

        p1.add(f1);

        p2.add(l2);

        p2.add(f2);

        p3.add(b1);

        p3.add(b2);

        p3.add(b3);

        cp.add(p1);

        cp.add(p2);

        cp.add(p3);

        b1.addActionListener(new Enter());

        b2.addActionListener(new ReWrite());

        b3.addActionListener(new Close());

        }

    class Enter implements ActionListener{

        public void actionPerformed(ActionEvent e)

        {      

                 if((f1.getText()).equals("czp")&&(f2.getText()).equals("123456"))

                 {        

                         

                         Yunsuan  frame1 = new Yunsuan();

                         frame1.setBounds(200, 200, 300, 300);

                         frame1.setVisible(true);

                 }

                 else JOptionPane.showMessageDialog(null, "用户名或密码错误，请重新登录！");

        }

    }

    class ReWrite implements ActionListener{

        public void actionPerformed(ActionEvent e)

        {

            f1.setText("");

            f2.setText("");

            f1.requestFocus();

        }

    }

    class Close implements ActionListener{

        public void actionPerformed(ActionEvent e)

        {

            JButton bt=(JButton)e.getSource();

            if(bt==b3){

                System.exit(0);

            }

        }

}

//主函数 程序开始

    public static void main(String[] args) {

        Login log=new Login();

        log.setTitle("系统登录");

        log.setBounds(200, 200, 300, 300);

        log.setBackground(Color.blue);

        log.setVisible(true);

         new Yunsuan();

         

    }

}



import java.awt.Color;

import java.awt.Container;

import java.awt.GridLayout;

import java.awt.Label;

import java.awt.Panel;

import java.awt.TextField;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.awt.event.WindowAdapter;

import java.awt.event.WindowEvent;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.io.ObjectInputStream;

import java.util.ArrayList;



import javax.swing.JButton;

import javax.swing.JComboBox;

import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JOptionPane;

import javax.swing.JPanel;

import javax.swing.JTextField;

public class Yunsuan extends JFrame {

    private  JTextField textNum1;

    private  JTextField textNum2;

    private  JTextField result;

    private  JTextField result1;

    private  JComboBox opers;

     

    public Yunsuan() {

        init();

        setSize(300,100);

        setLocationRelativeTo(null);

        setTitle("小学生运算");

        setDefaultCloseOperation(3);

        setVisible(false);

    }

     

    private void init(){

        String[] operators = "+,-,*,/".split(",");

        textNum1 = new JTextField();

        textNum1.setColumns(10);

        textNum2 = new JTextField();

        textNum2.setColumns(10);

        result = new JTextField();

        result.setColumns(10);

        result1= new JTextField();

        result1.setColumns(10);

        opers = new JComboBox(operators);

        opers.addActionListener(new ActionListener() {

            @Override

            public void actionPerformed(ActionEvent e) {

                int operator = opers.getSelectedIndex();

                double num1 = Double.parseDouble(textNum1.getText());

                double num2 = Double.parseDouble(textNum2.getText());

             switch(operator){

                case 0:result1.setText(num1 + num2+"");break;

                case 1:result1.setText(num1 - num2+"");break;

                case 2:result1.setText(num1 * num2+"");break;

                case 3:result1.setText(num1 / num2+"");break;

                }

                 

            }

           

        });

    

      

        

        JPanel p = new JPanel();

        p.add(textNum1);

        p.add(textNum2);

        p.add(opers);

        p.add(result);

        p.add(result1);

        this.add(p);

     

}

}