用java编写计算器_用Java编写一个简单的计算器

1、使用记事本或eclipse等编程工具，建立一个图形界面应用程序。

2、程序完成简单的四则计算功能

3、用户可以在名为Number1和Number2的文本输入框中输入2个操作数，然后点击下面的4个按钮之一，完成加、减、乘、除运算，并把运算结果输出到名为Result的文件夹中。

4、用户也可以通过使用Operation菜单中的四个菜单项(Add、Subtract、Mutiply、Divide)来完成相应的加、减、乘、除四则运算。

5、用户可以使用Exit菜单中的Close菜单项关闭程序窗体，结束程序运行；也可以直接点击窗体右上角的╳图标退出程序。

package 计算器;

import javax.swing.*;

import java.awt.*;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.awt.event.InputEvent;

import java.awt.event.KeyEvent;

import java.io.*;

public class 计算器 extends Frame {

public static void main(String[] args) {

JFrame c=new JFrame("Computer");

c.setLayout(new java.awt.FlowLayout());//设置布局

c.setBounds(400, 400, 500, 150);//确定窗口位置和大小

c.setResizable(false);

//菜单项

JMenuBar menubar= new JMenuBar();

c.setJMenuBar(menubar);

JMenu Operation=new JMenu("Operation");

JMenuItem Exit=new JMenuItem("Exit");

JMenuItem add=new JMenuItem("Add");

add.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_A,InputEvent.CTRL_MASK));

JMenuItem sub=new JMenuItem("Subtract");

sub.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_S,InputEvent.CTRL_MASK));

JMenuItem mul=new JMenuItem("Multiple");

mul.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_M,InputEvent.CTRL_MASK));

JMenuItem div=new JMenuItem("Divide");

div.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_D,InputEvent.CTRL_MASK));

menubar.add(Operation);

menubar.add(Exit);

Operation.add(add);

Operation.add(sub);

Operation.add(mul);

Operation.add(div);

//主页面

//文本框和加减乘除按钮

JTextField num1=new JTextField(6);

JTextField num2=new JTextField(6);

JTextArea res=new JTextArea(1,10);

JButton Badd=new JButton("Add");

JButton Bsub=new JButton("Subtract");

JButton Bmul=new JButton("Multiple");

JButton Bdiv=new JButton("Divide");

c.add(new JLabel("Number1"));

c.add(num1);

c.add(new JLabel("Number2"));

c.add(num2);

c.add(new JLabel("Result"));

c.add(res);

c.add(Badd);

c.add(Bsub);

c.add(Bmul);

c.add(Bdiv);

res.setEditable(false);

//添加监听器

Badd.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

try {

res.setText("");

double number1=Double.parseDouble(num1.getText());

double number2=Double.parseDouble(num2.getText());

double result=0;

result=number1+number2;

String str=new String();

res.append(str=""+result);

}

catch(Exception exp){

res.append("请输入数字字符");

}

}

});

Bsub.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

try {

res.setText("");

double number1=Double.parseDouble(num1.getText());

double number2=Double.parseDouble(num2.getText());

double result=0;

result=number1-number2;

String str;

res.append(str=""+result);

}

catch(Exception exp){

res.append("请输入数字字符");

}

}

});

Bmul.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

try {

res.setText("");

double number1=Double.parseDouble(num1.getText());

double number2=Double.parseDouble(num2.getText());

double result=0;

result=number1*number2;

String str=new String();

res.append(str=""+result);

}

catch(Exception exp){

res.append("请输入数字字符");

}

}

});

Bdiv.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

try {

res.setText("");

double number1=Double.parseDouble(num1.getText());

double number2=Double.parseDouble(num2.getText());

if(number2==0)

{

res.append("ERROR");

}

else {

double result=0;

result=number1/number2;

String str=new String();

res.append(str=""+result);

}

}

catch(Exception exp){

res.append("请输入数字字符");

}

}

});

add.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

try {

res.setText("");

double number1=Double.parseDouble(num1.getText());

double number2=Double.parseDouble(num2.getText());

double result=0;

result=number1+number2;

String str=new String();

res.append(str=""+result);

}

catch(Exception exp){

res.append("请输入数字字符");

}

}

});

sub.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

try {

res.setText("");

double number1=Double.parseDouble(num1.getText());

double number2=Double.parseDouble(num2.getText());

double result=0;

result=number1-number2;

String str;

res.append(str=""+result);

}

catch(Exception exp){

res.append("请输入数字字符");

}

}

});

mul.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

try {

res.setText("");

double number1=Double.parseDouble(num1.getText());

double number2=Double.parseDouble(num2.getText());

double result=0;

result=number1*number2;

String str=new String();

res.append(str=""+result);

}

catch(Exception exp){

res.append("请输入数字字符");

}

}

});

div.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

try {

res.setText("");

double number1=Double.parseDouble(num1.getText());

double number2=Double.parseDouble(num2.getText());

if(number2==0)

{

res.append("ERROR");

}

else {

double result=0;

result=number1/number2;

String str=new String();

res.append(str=""+result);

}

}

catch(Exception exp){

res.append("请输入数字字符");

}

}

});

Exit.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent e) {

System.exit(0);

}

});

c.setVisible(true);

}

}

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