基于JavaJDK的简易计算器(含源文件)

import java.awt.*;import java.awt.event.*;import javax.swing.*;import javax.swing.border.TitledBorder;public class calculator2 extends JFrame implements ActionListener {/****/private static final long serialV ersionUID = 1L;private boolean clickBeforeOperator; // 点击"+,-,*,/"等数学运算符和清除回车时// clickBeforeOperator = true private int firstInputChar; // 判断是否是第一次输入字符,firstInputChar = 0时是第一次输入private double answer; // 文本框中结果private int Operator;private DisplayPanel displaypanel = new DisplayPanel();private ButtonPanel buttonpanel = new ButtonPanel();private Point origin;private class DisplayPanel extends JPanel {/****/private static final long serialV ersionUID = 20120815L;private JTextField text;private JPanel del_clear = new JPanel();private JButton clear = new JButton("AC");private JButton del = new JButton("←");private TitledBorder title = new TitledBorder(null, "计算器------右键关闭", TitledBorder.DEFAULT_JUSTIFICA TION, TitledBorder.DEFAULT_POSITION, null, Color.white);public DisplayPanel() {text = new JTextField("",18);text.setBackground(Color.white); // 设置文本颜色text.setHorizontalAlignment(JTextField.RIGHT); // 设置右对齐text.setEditable(false); // 设置不可编辑del.setBackground(new Color(50, 50, 50));del.setForeground(Color.white);clear.setBackground(new Color(50, 50, 50));clear.setForeground(Color.white);del_clear.add(del);del_clear.add(clear);del_clear.setBackground(Color.black);this.setBackground(Color.black);this.setLayout(new BorderLayout()); // 面板设置为边布局this.add(text, BorderLayout.CENTER); // text文本行放在面板DisplayPanelthis.add(del_clear, BorderLayout.EAST);this.setBorder(title);}}public class ButtonPanel extends JPanel {/****/private static final long serialV ersionUID = 1L;private String button_str[] = { "7", "8", "9", "/", "4", "5", // 字符串数组"6", "*", "1", "2", "3", "-", // 做JButton的标签".", "0", "=", "+" };private JButton button[] = new JButton[button_str.length]; // 创建JButton按钮public ButtonPanel() {this.setLayout(new GridLayout(4, 4, 2, 2)); // 面板布局管理器设置为网格布局管理器this.setBackground(Color.black);for (int i = 0; i < button_str.length; i++) {button[i] = new JButton(button_str[i]);this.add(button[i]); // 在面板上添加button组件}// 设置button颜色for (int i = 0; i < button_str.length; i++) {if (i != 3 & i != 7 & i != 11 & i != 14 & i != 15) {button[i].setBackground(new Color(100, 100, 100));} else {button[i].setBackground(new Color(50, 50, 50));}button[i].setForeground(Color.white);}}}public calculator2() { // 构造方法super("计算器");try {UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());} catch (ClassNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (InstantiationException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IllegalAccessException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (UnsupportedLookAndFeelException e) {// TODO Auto-generated catch blocke.printStackTrace();}answer = 0;clickBeforeOperator = false; // 指示器firstInputChar = 0;Operator = -1;this.setBackground(Color.LIGHT_GRAY);this.setDefaultCloseOperation(EXIT_ON_CLOSE);this.getContentPane().setLayout(new BorderLayout(0, 1)); // 水平间距hgap = 0,垂直间距vgap=2this.getContentPane().setBackground(Color.black);this.getContentPane().add(displaypanel, "North"); // 框架"北"放置文本行textthis.getContentPane().add(buttonpanel, "Center"); // 框架"中"放置面板组件for (int i = 0; i < buttonpanel.button_str.length; i++) {buttonpanel.button[i].addActionListener(this);}displaypanel.del.addActionListener(this);displaypanel.clear.addActionListener(this);this.setBounds(300, 300, 250, 300);this.setResizable(false);this.setUndecorated(true);//由于隐藏了Frame边框，故一下做移动窗口和关闭的方法this.origin=new Point();addMouseListener(new MouseAdapter(){public void mousePressed(MouseEvent e){origin.x = e.getX();origin.y = e.getY();}//窗体上单击鼠标右键关闭程序public void mouseClicked(MouseEvent e) {if(e.getButton()==MouseEvent.BUTTON3)System.exit(0);}public void mouseReleased(MouseEvent e) {super.mouseReleased(e);}@Overridepublic void mouseEntered(MouseEvent e) {repaint();}});addMouseMotionListener(new MouseMotionAdapter(){public void mouseDragged(MouseEvent e){Point p = getLocation();setLocation(p.x + e.getX() - origin.x, p.y + e.getY() - origin.y );}});this.setV isible(true);}public void actionPerformed(ActionEvent e) {String button_label = e.getActionCommand();// ******************************输入double型数据********************************if ((button_label.charAt(0) >= '0' && button_label.charAt(0) <= '9')|| button_label == ".") {if (clickBeforeOperator == true || firstInputChar == 0) { // 如果点击了运算符，清除回车等按键，再点击数字键displaypanel.text.setText("" + button_label);clickBeforeOperator = false;firstInputChar = 1;} else {if (!(button_label == ".")) // 如果输入数字{displaypanel.text.setText(displaypanel.text.getText()+ button_label);}if (button_label == ".") { // 如果输入点boolean isContainerPoint = false; // 判断逻辑量if (displaypanel.text.getText().equals("")) // 如果文本行中字符串为空{isContainerPoint = true;displaypanel.text.setText("0.");}for (int i = 0; i < displaypanel.text.getText().length(); i++) // 判断文本行中字符串是否已含小数点{if (displaypanel.text.getText().charAt(i) == '.') {isContainerPoint = true;}}if (isContainerPoint == false) {displaypanel.text.setText(displaypanel.text.getText()+ ".");}}}}// **************************************清除键*************************************if (button_label == "AC") {displaypanel.text.setText("");clickBeforeOperator = true;firstInputChar = 0;}// **************************************删除*************************************try // 异常处理{if (button_label == "←") {String str = displaypanel.text.getText();displaypanel.text.setText(str.substring(0, str.length() - 1)); // 最初此语句无效？？？？why，当把回车键标签名设置为BackSpace时，此语句失效clickBeforeOperator = true;firstInputChar = 0; // BackSpace字符串长度过长,导致界面上无法显示全部字符串，故无法实现此功能}} catch (StringIndexOutOfBoundsException sioobe) {JOptionPane.showMessageDialog(this, "已空，无法继续删除");}finally {}// ***************************************加减乘除运算*****************************************if (button_label == "+" || button_label == "-" || button_label == "*"|| button_label == "/") {if (button_label == "+") {clickBeforeOperator = true;firstInputChar = 0;answer = Double.parseDouble(displaypanel.text.getText());Operator = 0;}if (button_label == "-") {clickBeforeOperator = true;firstInputChar = 0;answer = Double.parseDouble(displaypanel.text.getText());Operator = 1;}if (button_label == "*") {clickBeforeOperator = true;firstInputChar = 0;answer = Double.parseDouble(displaypanel.text.getText());Operator = 2;}if (button_label == "/") {clickBeforeOperator = true;firstInputChar = 0;answer = Double.parseDouble(displaypanel.text.getText());Operator = 3;}}if (button_label == "=") {switch (Operator) {case 0:answer += Double.parseDouble(displaypanel.text.getText());displaypanel.text.setText("" + answer);firstInputChar = 0;break;case 1:answer -= Double.parseDouble(displaypanel.text.getText());displaypanel.text.setText("" + answer);firstInputChar = 0;break;case 2:answer *= Double.parseDouble(displaypanel.text.getText());displaypanel.text.setText("" + answer);firstInputChar = 0;break;case 3:if (Double.parseDouble(displaypanel.text.getText()) == 0) {JOptionPane.showMessageDialog(this, "除数不能为零");} else {answer /= Double.parseDouble(displaypanel.text.getText());displaypanel.text.setText("" + answer);firstInputChar = 0;}break;}}}public static void main(String args[]) {new calculator2();}}。

简易计算器（Android应用使用Java开发）随着智能手机的普及，手机应用程序也变得越来越多样化和智能化。

其中，计算器应用无疑是人们生活中最常用的一种应用之一。

本文将介绍如何使用Java开发一个简易计算器的Android应用程序。

1. 概述简易计算器是一款可以进行基本的数学计算的应用程序。

用户可以在界面上输入数字和操作符，计算器会自动根据用户的操作给出计算结果。

本应用程序采用Java语言进行开发，运行于Android操作系统。

2. 开发环境在开始开发前，我们需要搭建好Android开发环境。

首先，下载并安装Java Development Kit（JDK），确保版本为最新稳定版。

然后，下载并安装Android Studio，这是一款为Android开发而设计的集成开发环境（IDE）。

3. 创建项目打开Android Studio，并点击"Start a new Android Studio project"来创建一个新的项目。

在弹出的窗口中，填写项目名称、包名等基本信息，并选择适当的设备和目标SDK版本。

4. 设计界面在项目创建完成后，我们需要设计计算器的界面。

可以使用Android Studio自带的可视化UI设计器来拖拽和放置UI元素，也可以手动在XML布局文件中编写界面代码。

界面的核心组件包括输入框、按钮和显示区域。

5. 添加逻辑功能界面设计完成后，我们需要为计算器添加逻辑功能。

创建一个Java类作为计算器的主活动（Activity），在其中实现输入和操作的处理逻辑。

可以使用Android提供的计算相关API，例如使用eval()方法进行表达式计算。

6. 编译和调试在开发过程中，我们可以随时进行编译和调试来检查应用程序的运行情况。

点击Android Studio的运行按钮，选择目标设备并运行应用程序。

在模拟器或真机上进行调试，查看是否符合我们的预期效果。

7. 测试和发布在功能开发和调试完毕后，我们需要进行应用的测试阶段。

用java编写的计算器（Calculator）import java.io.*;import java.awt.*;import java.awt.event.*;import java.util.*;public class Calculator{public static void main(String[] args){new MyfirstCalculator();}}class MyfirstCalculator{Frame f=new Frame("calculator");TextField tf=new T extField(50);ArrayList sa=new ArrayList();//sa用来存储sb中的数据StringBuilder sb=new StringBuilder();//sb用来存储0-9中的数据StringBuilder sb1=new StringBuilder();//用作判断，里面数据为:+,-,*,/四个中的任意一个或多个StringBuilder sb2=new StringBuilder();//用作判断，里面数据为:=MyfirstCalculator(){init();}public void init(){Button b0=new Button("0");Button b1=new Button("1");Button b2=new Button("2");Button b3=new Button("3");Button b4=new Button("4");Button b5=new Button("5");Button b6=new Button("6");Button b7=new Button("7");Button b8=new Button("8");Button b9=new Button("9");Button ba=new Button("=");Button bb=new Button("-");Button bc=new Button("+");Button bd=new Button("*");Button be=new Button("/");//Button bf=new Button("D");//定义一个清空按钮,用来从头开始计数f.add(tf);f.add(b0);f.add(b1);f.add(b2);f.add(b3);f.add(b4);f.add(b5);f.add(b6);f.add(b7);f.add(b8);f.add(b9);f.add(ba);f.add(bb);f.add(bc);f.add(bd);f.add(be);//f.add(bf);f.setBounds(400,400,300,300);f.setVisible(true);f.setLayout(new GridLayout(4,4));//下面的b[0-9]为按钮事件,让点击的按钮数字能够在TextField(tf)中能够显示b0.addActionListener(new ActionListener(){public void actionPerformed(ActionEvent e){if(sb2.indexOf("=")!=-1){sb.delete(0,sb.length());//在按"="之后在按0-9之间的数字,就清空sb 中的数据,从头开始计数}tf.setText("");sb.append(0);//点击数字按钮，就在sb中加一个数字;tf.setText(sb.toString());//在tf中显示按钮所输入的数字}});b1.addActionListener(new ActionListener(){public void actionPerformed(ActionEvent e) //下面同b0判断的方法一样{if(sb2.indexOf("=")!=-1){sb.delete(0,sb.length());}tf.setText("");sb.append("1");tf.setText(sb.toString());}});b2.addActionListener(new ActionListener(){public void actionPerformed(ActionEvent e) //下面同b0判断的方法一样{if(sb2.indexOf("=")!=-1){sb.delete(0,sb.length());}tf.setText("");sb.append("2");tf.setText(sb.toString());}});b3.addActionListener(new ActionListener(){public void actionPerformed(ActionEvent e) //下面同b0判断的方法一样{if(sb2.indexOf("=")!=-1){sb.delete(0,sb.length());}tf.setText("");sb.append("3");tf.setText(sb.toString());}});b4.addActionListener(new ActionListener(){public void actionPerformed(ActionEvent e) //下面同b0判断的方法一样{if(sb2.indexOf("=")!=-1){sb.delete(0,sb.length());}tf.setText("");sb.append("4");tf.setText(sb.toString());}});b5.addActionListener(new ActionListener(){public void actionPerformed(ActionEvent e) //下面同b0判断的方法一样{if(sb2.indexOf("=")!=-1){sb.delete(0,sb.length());}tf.setText("");sb.append("5");tf.setText(sb.toString());}});b6.addActionListener(new ActionListener()public void actionPerformed(ActionEvent e) //下面同b0判断的方法一样{if(sb2.indexOf("=")!=-1){sb.delete(0,sb.length());}tf.setText("");sb.append("6");tf.setText(sb.toString());}});b7.addActionListener(new ActionListener(){public void actionPerformed(ActionEvent e) //下面同b0判断的方法一样{if(sb2.indexOf("=")!=-1){sb.delete(0,sb.length());}tf.setText("");sb.append("7");tf.setText(sb.toString());}});b8.addActionListener(new ActionListener(){public void actionPerformed(ActionEvent e) //下面同b0判断的方法一样{if(sb2.indexOf("=")!=-1)sb.delete(0,sb.length());}tf.setText("");sb.append("8");tf.setText(sb.toString());}});b9.addActionListener(new ActionListener(){public void actionPerformed(ActionEvent e) //下面同b0判断的方法一样{if(sb2.indexOf("=")!=-1){sb.delete(0,sb.length());}sb.append("9");tf.setText(sb.toString());}});//bc在此处为"+"事件，调动"-"(bb),"*"(bd),"/"(be)这三个中的其中一个算法bc.addActionListener(new ActionListener(){public void actionPerformed(ActionEvent e){sa.add(sb.toString());//把sb中的数据即tf(TextField)中显示的数据添加到sa 集合中,用于做加减乘除运算sb.delete(0,sb.length());//清空sb中的缓存,以便于sb存入tf中显示的下一个数字sb1.append("+");//当点击"="按钮,"+"用作加法运算判断的标志sb2.delete(0,sb2.length());//清空sb2中的数据/*//此处为加法运算,--测试代码if(sb1.indexOf("+")!=-1)){int sum=0;for(String s:sa){sum+=Integer.parseInt(s);}//sb1.append("+");System.out.println("+2..."+sum);sa.clear();sa.add(""+sum);System.out.println(sa);tf.setText(""+sum);//sa.add(sb.toString());System.out.println("+..."+sa);sb.delete(0,sb.length());sb1.delete(0,sb1.length());sb1.append("+");}*///此处为减法运算if(sb1.indexOf("-")!=-1){int sum=0;int count=0;for(String s:sa){if(count==0){sum=Integer.parseInt(s);//System.out.println(""+sum);--测试代码} else{sum+=-(Integer.parseInt(s));}count++;}//System.out.println("-2..."+sum);--测试代码sa.clear();sa.add(""+sum);//System.out.println(sa);--测试代码tf.setText(""+sum);//System.out.println("-..."+sa);--测试代码sb.delete(0,sb.length());sb1.delete(0,sb1.length());sb1.append("+");}//此处为乘法运算if(sb1.indexOf("*")!=-1){int sum=1;for(String s:sa){sum=sum*Integer.parseInt(s);}//System.out.println("*2..."+sum);--测试代码sa.clear();sa.add(""+sum);//System.out.println(sa);--测试代码tf.setText(""+sum);//System.out.println("*..."+sa);--测试代码sb.delete(0,sb.length());sb1.delete(0,sb1.length());sb1.append("+");}//此处为除法运算if(sb1.indexOf("/")!=-1){int sum=0;int count=0;for(String s:sa){if(count==0){sum=Integer.parseInt(s);}else{sum/=Integer.parseInt(s);}count++;}//System.out.println("-2..."+sum);--测试代码sa.clear();sa.add(""+sum);//System.out.println(sa);--测试代码tf.setText(""+sum);//System.out.println("/..."+sa);--测试代码sb.delete(0,sb.length());sb1.delete(0,sb1.length());sb1.append("+");}}});//ba在此处为"="事件，调动"-"(bb),"+"(ba),"*"(bd),"/"(be),这四个中的其中一个算法ba.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e){if(sa.size()==0)//当sa集合中没有元素,即就没有任何数字用于做加减乘除运算，就中断程序return;if(sb1.indexOf("+")!=-1)//加法运算判断{sa.add(sb.toString());//System.out.println("+1..."+sa);--测试代码int sum=0;for(String s:sa){sum+=Integer.parseInt(s);}//System.out.println(""+sum);--测试代码tf.setText(""+sum);//把算出的结果显示在tf中sa.clear();//清空集合中的元素,以便于做下一个运算sb.delete(0,sb.length());sb.append(""+sum);//当点击"="按钮后,再点击"-","+","*","/"中的任意一个按钮,就要把结果存入到sa集合中,用与下一个数字做运算//sa.append(""+sum);--测试代码sb1.delete(0,sb1.length());sb2.append("=");}if(sb1.indexOf("-")!=-1)//减法运算判断{sa.add(sb.toString());System.out.println("-1..."+sa);int sum=0;int count=0;for(String s:sa){if(count==0){sum=Integer.parseInt(s);//System.out.println(""+sum);--测试代码}else{sum+=-(Integer.parseInt(s));}count++;}//System.out.println(""+sum);--测试代码tf.setText(""+sum);sb.delete(0,sb.length());sb.append(""+sum);sa.clear();sb1.delete(0,sb1.length());sb2.append("=");}if (sb1.indexOf("*")!=-1)//乘法运算判断{ sa.add(sb.toString());//System.out.println("*1..."+sa);int sum=1;for(String s:sa){sum=sum*Integer.parseInt(s);}//System.out.println(""+sum);--测试代码tf.setText(""+sum);sb.delete(0,sb.length());sa.clear();sb.append(""+sum);sb1.delete(0,sb1.length());sb2.append("=");}if(sb1.indexOf("/")!=-1)//除法运算判断{sa.add(sb.toString());System.out.println("/.."+sa);int sum=0;int count=0;for(String s:sa){if(count==0){sum=Integer.parseInt(s);}else{sum/=Integer.parseInt(s);}count++;}//System.out.println(""+sum);--测试代码tf.setText(""+sum);sb.delete(0,sb.length());sa.clear();sb.append(""+sum);sb2.append("=");}sb1.delete(0,sb1.length());}});//bb在此处为"-"事件，调动"+"(bc),"*"(bd),"/"(be)这三个中的其中一个算法bb.addActionListener(new ActionListener() //下面同bc("+")事件判断的方法一样{public void actionPerformed(ActionEvent e){sa.add(sb.toString());System.out.println("-..."+sa);sb.delete(0,sb.length());sb1.append("-");sb2.delete(0,sb2.length());if(sb1.indexOf("+")!=-1){int sum=0;for(String s:sa){sum+=Integer.parseInt(s);}//System.out.println("+2..."+sum);--测试代码sa.clear();sa.add(""+sum);//System.out.println(sa);--测试代码tf.setText(""+sum);//System.out.println("+..."+sa);--测试代码sb.delete(0,sb.length());sb1.delete(0,sb1.length());sb1.append("-");}/*--测试代码if(sb1.indexOf("-")!=-1){int sum=0;int count=0;for(String s:sa){if(count==0){sum=Integer.parseInt(s);//System.out.println(""+sum);}else{sum+=-(Integer.parseInt(s));}count++;}sb1.append("-");System.out.println("-2..."+sum);sa.clear();sa.add(""+sum);System.out.println(sa);tf.setText(""+sum);sa.add(sb.toString());System.out.println("*..."+sa);sb.delete(0,sb.length());sb1.delete(0,sb1.length());sb1.append("/");}*/if(sb1.indexOf("*")!=-1){int sum=1;for(String s:sa){sum=sum*Integer.parseInt(s);}//System.out.println("*2..."+sum);--测试代码sa.clear(); sa.add(""+sum);//System.out.println(sa);--测试代码tf.setText(""+sum);//System.out.println("*..."+sa);--测试代码sb.delete(0,sb.length());sb1.delete(0,sb1.length());sb1.append("-");}if(sb1.indexOf("/")!=-1){int sum=0;int count=0;for(String s:sa){if(count==0){sum=Integer.parseInt(s);}else{sum/=Integer.parseInt(s);}count++;}//System.out.println("-2..."+sum);--测试代码sa.clear();sa.add(""+sum);//System.out.println(sa);--测试代码tf.setText(""+sum);//System.out.println("-..."+sa);--测试代码sb.delete(0,sb.length());sb1.delete(0,sb1.length());sb1.append("-");}}});//bd在此处为"*"事件，调动"-"(bb),"+"(bc),"/"(be)这三个中的其中一个算法bd.addActionListener(new ActionListener(){public void actionPerformed(ActionEvent e) //下面同bc("+")事件判断的方法一样{sa.add(sb.toString());sb.delete(0,sb.length());sb1.append("*");sb2.delete(0,sb2.length());if(sb1.indexOf("+")!=-1){int sum=0;for(String s:sa){sum+=Integer.parseInt(s);}//System.out.println("+2..."+sum);--测试代码sa.clear();sa.add(""+sum);//System.out.println(sa);--测试代码tf.setText(""+sum);//System.out.println("*..."+sa);--测试代码sb.delete(0,sb.length());sb1.delete(0,sb1.length());sb1.append("*");}if(sb1.indexOf("-")!=-1){int sum=0;int count=0;for(String s:sa){if(count==0){sum=Integer.parseInt(s);//System.out.println(""+sum);--测试代码} else{sum+=-(Integer.parseInt(s));}count++;}//System.out.println("-2..."+sum);--测试代码sa.clear();sa.add(""+sum);//System.out.println(sa);--测试代码tf.setText(""+sum);//System.out.println("*..."+sa);--测试代码sb.delete(0,sb.length());sb1.delete(0,sb1.length());sb1.append("*");}if(sb1.indexOf("/")!=-1){int sum=0;int count=0;for(String s:sa){if(count==0){sum=Integer.parseInt(s);}else{sum/=Integer.parseInt(s);}count++;}//System.out.println("/2..."+sum);--测试代码sa.clear();sa.add(""+sum);//System.out.println(sa);--测试代码tf.setText(""+sum);//System.out.println("*..."+sa);--测试代码sb.delete(0,sb.length());sb1.delete(0,sb1.length());sb1.append("*");}/*--测试代码int sum=1;for(String s:sa){sum=sum*Integer.parseInt(s);}sb1.append("*");System.out.println(""+sum);tf.setText(""+sum);*/}//be在此处为"/"事件，调动"-"(bb),"*"(bd),"+"(bc)这三个中的其中一个算法be.addActionListener(new ActionListener(){public void actionPerformed(ActionEvent e) //下面同bc("+")事件判断的方法一样{sa.add(sb.toString());System.out.println("+.."+sa);sb.delete(0,sb.length());sb1.append("+");//sb2.delete(0,sb2.length());if(sb1.indexOf("+")!=-1){int sum=0;for(String s:sa){sum+=Integer.parseInt(s);}sa.clear();sa.add(""+sum);//System.out.println(sa);--测试代码tf.setText(""+sum);//System.out.println("*..."+sa);--测试代码sb.delete(0,sb.length());sb1.delete(0,sb1.length());sb1.append("/");}if(sb1.indexOf("-")!=-1)int sum=0;int count=0;for(String s:sa){if(count==0){sum=Integer.parseInt(s);//System.out.println(""+sum);--测试代码} else{sum+=-(Integer.parseInt(s));}count++;}//System.out.println("-2..."+sum);--测试代码sa.clear();sa.add(""+sum);//System.out.println(sa);--测试代码tf.setText(""+sum);//System.out.println("*..."+sa);--测试代码sb.delete(0,sb.length());sb1.delete(0,sb1.length());sb1.append("/");}if(sb1.indexOf("*")!=-1){int sum=1;for(String s:sa){sum=sum*Integer.parseInt(s);}sa.clear();sa.add(""+sum);//System.out.println(sa);--测试代码tf.setText(""+sum);//System.out.println("*..."+sa);--测试代码sb.delete(0,sb.length());sb1.delete(0,sb1.length());sb1.append("/");}/*--测试代码int sum=0;int count=0;for(String s:sa){if(count==0){sum=Integer.parseInt(s);}else{sum/=Integer.parseInt(s);}count++;}System.out.println(""+sum);sb1.append("/");tf.setText(""+sum);*/}});//定义一个清除器事件，清空所用数据用--测试代码/* bf.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) {sb.delete(0,sb.length());}});*///关闭窗口f.addWindowListener(new WindowAdapter() {public void windowClosing(WindowEvent e) {System.exit(0);}});}}。

/*使用java 语言开发一个简易计算器***/public class TestJsq extends JFrame implements ActionListener, KeyListener { private JTextField jtf;private JButton jb_bk, jb_ce, jb_c;private String xs = "";private double sum = 0;private int fh;public static void main(String[] args) {new TestJsq().creatCUI();}public void creatCUI() {JFrame jf = new JFrame();jf.setTitle("计算器");jtf = new JTextField("0.");jtf.setHorizontalAlignment(JTextField.RIGHT);jf.add(jtf, BorderLayout.NORTH);JPanel jp_main = new JPanel(new BorderLayout());jf.add(jp_main);JPanel jp1 = new JPanel(new GridLayout(1, 3, 1, 1));jb_bk = new JButton("Backspace");jb_bk.setForeground(Color.RED);jb_bk.addActionListener(this);jb_ce = new JButton("CE");jb_ce.setForeground(Color.RED);jb_ce.addActionListener(this);jb_c = new JButton("C");jb_c.setForeground(Color.RED);jb_c.addActionListener(this);jp1.add(jb_bk);jp1.add(jb_ce);jp1.add(jb_c);jp_main.add(jp1, BorderLayout.NORTH);JPanel jp2 = new JPanel(new GridLayout(4, 5, 1, 1));String str[] = { "7", "8", "9", "/", "sqrt", "4", "5", "6", "*", "%", "1", "2", "3", "-", "1/x", "0", "+/-", ".", "+", "=" };for (int i = 0; i < 20; i++) {JButton jb = new JButton(str[i]);jb.addActionListener(this);jb.setForeground(Color.blue);if (i == 3 || i == 8 || i == 13 || i == 18 || i == 19) {jb.setForeground(Color.RED);}jp2.add(jb);}jp_main.add(jp2, BorderLayout.CENTER);jf.setResizable(false);jf.setBounds(50, 50, 350, 350);jf.setVisible(true);}@Overridepublic void actionPerformed(ActionEvent e) {String s = e.getActionCommand();if (s.equals("CE") || s.equals("C")) {xs = "";jtf.setText("0.");} else if (s.equals("Backspace")) {String str = xs.substring(0, xs.length() - 1);xs = str;jtf.setText(xs);} else if (s.equals("7") || s.equals("8") || s.equals("9")|| s.equals("4") || s.equals("5") || s.equals("6")|| s.equals("1") || s.equals("2") || s.equals("3")|| s.equals("0") || s.equals(".")) {xs = xs + s;jtf.setText(xs);} else if (s.equals("+/-")) {double x = Double.parseDouble(xs);xs="" + (-x);jtf.setText(xs);} else if (s.equals("/")) {fh = 4;int point = xs.indexOf(".");if (point != -1) {String strt = xs.substring(0, point);String z = xs.substring(point + 1, xs.length());int z_num = z.length();sum = Integer.decode(strt) + (double) (Integer.decode(z))/ (10 * z_num);} else {sum = Integer.decode(xs);}xs = "";jtf.setText(null);} else if (s.equals("*")) {fh = 3;int point = xs.indexOf(".");if (point != -1) {String strt = xs.substring(0, point);String z = xs.substring(point + 1, xs.length());int z_num = z.length();sum = Integer.decode(strt) + (double) (Integer.decode(z)) / (10 * z_num);} else {sum = Integer.decode(xs);}xs = "";jtf.setText(null);} else if (s.equals("-")) {fh = 2;int point = xs.indexOf(".");if (point != -1) {String strt = xs.substring(0, point);String z = xs.substring(point + 1, xs.length());int z_num = z.length();sum = Integer.decode(strt) + (double) (Integer.decode(z)) / (10 * z_num);} else {sum = Integer.decode(xs);}xs = "";jtf.setText(null);} else if (s.equals("+")) {fh = 1;int point = xs.indexOf(".");if (point != -1) {String strt = xs.substring(0, point);String z = xs.substring(point + 1, xs.length());int z_num = z.length();sum = Integer.decode(strt) + (double) (Integer.decode(z)) / (10 * z_num);} else {sum = Integer.decode(xs);}xs = "";jtf.setText(null);} else if (s.equals("sqrt")) {double x = Double.parseDouble(xs);double x1 = Math.sqrt(x);xs = x1 + "";jtf.setText(xs);} else if (s.equals("%")) {double x = Double.parseDouble(xs);x=0.01 * x*x;xs=x+"";jtf.setText(xs);} else if (s.equals("1/x")) {if (xs == "0") {jtf.setText("除数不能为0");} else {double x = Double.parseDouble(xs);double x1 = 1 / x;xs = x1 + "";jtf.setText(String.valueOf(xs));}} else if (s.equals("=")) {if (fh != 0) {switch (fh) {case 1:int point1 = xs.indexOf(".");if (point1 != -1) {String s1 = xs.substring(0, point1);String z1 = xs.substring(point1 + 1, xs.length());int z1_num = z1.length();xs = "";double ss1 = Integer.decode(s1)+ (double) Integer.decode(z1) / (10 * z1_num);sum = sum + ss1;} else {sum = sum + Integer.decode(xs);xs = "";}fh = 0;break;case 2:int point2 = xs.indexOf(".");if (point2 != -1) {String s2 = xs.substring(0, point2);String z2 = xs.substring(point2 + 1, xs.length());int z2_num = z2.length();xs = "";double ss2 = Integer.decode(s2)+ (double) Integer.decode(z2) / (10 * z2_num);sum = sum - ss2;} else {sum = sum - Integer.decode(xs);xs = "";}fh = 0;break;case 3:int point3 = xs.indexOf(".");if (point3 != -1) {String s3 = xs.substring(0, point3);String z3 = xs.substring(point3 + 1, xs.length());int z1_num = z3.length();xs = "";double s4 = Integer.decode(s3)+ (double) Integer.decode(z3) / (10 * z1_num);sum = sum * s4;} else {sum = sum * Integer.decode(xs);xs = "";}fh = 0;break;case 4:int point4 = xs.indexOf(".");if (point4 != -1) {String s4 = xs.substring(0, point4);String z4 = xs.substring(point4 + 1, xs.length());int z4_num = z4.length();xs = "";double s5 = Integer.decode(s4)+ (double) Integer.decode(z4) / (10 * z4_num);sum = sum / s5;} else {sum = sum / Integer.decode(xs);xs = "";}fh = 0;break;default:break;}xs = String.valueOf(sum);jtf.setText(xs);fh = 0;} else {jtf.setText(null);}}}@Overridepublic void keyPressed(KeyEvent e) {// TODO Auto-generated method stub}@Overridepublic void keyReleased(KeyEvent e) { // TODO Auto-generated method stub }@Overridepublic void keyTyped(KeyEvent e) {// TODO Auto-generated method stub }}。