制作实时计算java代码 java 实时计算

如何用JAVA语言编写计算器小程序？

具体代码如下：

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import javax.swing.*;

import java.awt.event.*;

import java.awt.*;

public class Calculator  extends JFrame implements ActionListener  {

private JFrame jf;

private JButton[] allButtons;

private JButton clearButton;

private JTextField jtf;

public Calculator() {

//对图形组件实例化

jf=new JFrame("任静的计算器1.0：JAVA版");

jf.addWindowListener(new WindowAdapter(){

public void windowClosing(){

System.exit(0);

}

});

allButtons=new JButton[16];

clearButton=new JButton("清除");

jtf=new JTextField(25);

jtf.setEditable(false);

String str="123+456-789*0.=/";

for(int i=0;iallButtons.length;i++){

allButtons[i]=new JButton(str.substring(i,i+1));

}

}

public void init(){

//完成布局

jf.setLayout(new BorderLayout());

JPanel northPanel=new JPanel();

JPanel centerPanel=new JPanel();

JPanel southPanel=new JPanel();

northPanel.setLayout(new FlowLayout());

centerPanel.setLayout(new GridLayout(4,4));

southPanel.setLayout(new FlowLayout());

northPanel.add(jtf);

for(int i=0;i16;i++){

centerPanel.add(allButtons[i]);

}

southPanel.add(clearButton);

jf.add(northPanel,BorderLayout.NORTH);

jf.add(centerPanel,BorderLayout.CENTER);

jf.add(southPanel,BorderLayout.SOUTH);

addEventHandler();

}

//添加事件监听

public void addEventHandler(){

jtf.addActionListener(this);

for(int i=0;iallButtons.length;i++){

allButtons[i].addActionListener(this);

}

clearButton.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent e) {

// TODO Auto-generated method stub

Calculator.this.jtf.setText("");

}

});

}

//事件处理

public void actionPerformed(ActionEvent e) {

//在这里完成事件处理  使计算器可以运行

String action=e.getActionCommand();

if(action=="+"||action=="-"||action=="*"||action=="/"){

}

}

public void setFontAndColor(){

Font f=new Font("宋体",Font.BOLD,24);

jtf.setFont(f);

jtf.setBackground(new Color(0x8f,0xa0,0xfb));

for(int i=0;i16;i++){

allButtons[i].setFont(f);

allButtons[i].setForeground(Color.RED);

}

}

public void showMe(){

init();

setFontAndColor();

jf.pack();

jf.setVisible(true);

jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

public static void main(String[] args){

new Calculator().showMe();

}

}

用Java或C++写一个计算器，如图所示的？

采用java编写一个简单计算器，使用awt和swing

代码如下：

import java.awt.Color;

import java.awt.Font;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JPanel;

/*用java做一个计算器

* 实现整数和小数的加减乘除

* 具有删除和复位功能

*/

public class CaculatorDemo extends JFrame {

private static final long serialVersionUID = 1L;

private StringBuilder sBuilder = new StringBuilder();

private Double a;//中间变量用于存储输入的第一个数

private Double b;//中间变量，用于存储输入的第二个数

private Double double1;//用于接收计算结果

private Integer i;// i用于表示加减乘除

public CaculatorDemo() {

this.setTitle("计算器");

this.setSize(318, 457);

this.setLocationRelativeTo(null);

this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

JPanel panel = new JPanel();

this.getContentPane().add(panel);

panel.setLayout(null);

// 定义一个label用于显示输入数据和计算结果，这里不用textfield，可以避免用户输入造成bug，简化程序开发

final JLabel label = new JLabel();

label.setBounds(0, 0, 300, 50);

label.setFont(new Font("dialog", 1, 30));

label.setOpaque(true);// 由于jlabel默认透明，直接设置背景色无效，需要先将不透明设置为true

label.setBackground(Color.white);

panel.add(label);

// 定义按钮组件

JButton button1 = new JButton("1");

JButton button2 = new JButton("2");

JButton button3 = new JButton("3");

JButton button4 = new JButton("4");

JButton button5 = new JButton("5");

JButton button6 = new JButton("6");

JButton button7 = new JButton("7");

JButton button8 = new JButton("8");

JButton button9 = new JButton("9");

JButton button0 = new JButton("0");

JButton buttonadd = new JButton("+");// 加

JButton buttonminus = new JButton("-");// 减

JButton buttontime = new JButton("×");// 乘

JButton buttondivid = new JButton("÷");// 除

JButton buttonequal = new JButton("=");// 等于

JButton buttondecimal = new JButton(".");// 小数点

JButton buttondelet = new JButton("←");// 删除

JButton buttonclear = new JButton("C");// 清除

// 定义按钮组件位置

button0.setBounds(0, 50, 100, 60);

button0.setFont(new Font("dialog", 1, 30));

panel.add(button0);

button1.setBounds(100, 50, 100, 60);

button1.setFont(new Font("dialog", 1, 30));

panel.add(button1);

button2.setBounds(200, 50, 100, 60);

button2.setFont(new Font("dialog", 1, 30));

panel.add(button2);

button3.setBounds(0, 110, 100, 60);

button3.setFont(new Font("dialog", 1, 30));

panel.add(button3);

button4.setBounds(100, 110, 100, 60);

button4.setFont(new Font("dialog", 1, 30));

panel.add(button4);

button5.setBounds(200, 110, 100, 60);

button5.setFont(new Font("dialog", 1, 30));

panel.add(button5);

button6.setBounds(0, 170, 100, 60);

button6.setFont(new Font("dialog", 1, 30));

panel.add(button6);

button7.setBounds(100, 170, 100, 60);

button7.setFont(new Font("dialog", 1, 30));

panel.add(button7);

button8.setBounds(200, 170, 100, 60);

button8.setFont(new Font("dialog", 1, 30));

panel.add(button8);

button9.setBounds(0, 230, 100, 60);

button9.setFont(new Font("dialog", 1, 30));

panel.add(button9);

buttonadd.setBounds(100, 230, 100, 60);

buttonadd.setFont(new Font("dialog", 1, 30));

panel.add(buttonadd);//加

buttonminus.setBounds(200, 230, 100, 60);

buttonminus.setFont(new Font("dialog", 1, 30));

panel.add(buttonminus);//减

buttontime.setBounds(0, 290, 100, 60);

buttontime.setFont(new Font("dialog", 1, 30));

panel.add(buttontime);//乘

buttondivid.setBounds(100, 290, 100, 60);

buttondivid.setFont(new Font("dialog", 1, 30));

panel.add(buttondivid);//除

buttonequal.setBounds(200, 290, 100, 60);

buttonequal.setFont(new Font("dialog", 1, 30));

panel.add(buttonequal);//等于

buttondecimal.setBounds(0, 350, 100, 60);

buttondecimal.setFont(new Font("dialog", 1, 30));

panel.add(buttondecimal);//小数点

buttonclear.setBounds(100, 350, 100, 60);

buttonclear.setFont(new Font("dialog", 1, 30));

panel.add(buttonclear);//复位

buttondelet.setBounds(200, 350, 100, 60);

buttondelet.setFont(new Font("dialog", 1, 30));

panel.add(buttondelet);//删除

// 给各个按钮设置动作监听器

// 输入数值操作0~9

button0.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

sBuilder.append("0");

label.setText(sBuilder.toString());

}

});

button1.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

sBuilder.append("1");

label.setText(sBuilder.toString());

}

});

button2.addActionListener(new ActionListener() {

@Override

public void actionPerformed(ActionEvent e) {

sBuilder.append("2");

label.setText(sBuilder.toString());

}

});

button3.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

sBuilder.append("3");

label.setText(sBuilder.toString());

}

});

button4.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

sBuilder.append("4");

label.setText(sBuilder.toString());

}

});

button5.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

sBuilder.append("5");

label.setText(sBuilder.toString());

}

});

button6.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

sBuilder.append("6");

label.setText(sBuilder.toString());

}

});

button7.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

sBuilder.append("7");

label.setText(sBuilder.toString());

}

});

button8.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

sBuilder.append("8");

label.setText(sBuilder.toString());

}

});

button9.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

sBuilder.append("9");

label.setText(sBuilder.toString());

}

});

// 输入运算符操作，需要先判断a是否为0.0

buttonadd.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

a = Double.parseDouble(sBuilder.toString());

sBuilder = new StringBuilder();

label.setText("+");

i = 0;

}

});

buttonminus.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

a = Double.parseDouble(sBuilder.toString());

sBuilder = new StringBuilder();

label.setText("-");

i = 1;

}

});

buttontime.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

a = Double.parseDouble(sBuilder.toString());

sBuilder = new StringBuilder();

label.setText("×");

i = 2;

}

});

buttondivid.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

a = Double.parseDouble(sBuilder.toString());

sBuilder = new StringBuilder();

label.setText("÷");

i = 3;

}

});

buttonequal.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

// 该判断中间变量是否为空

if (!"".equals(sBuilder.toString()) (!(a == 0.0))) {

b = Double.parseDouble(sBuilder.toString());

if (i == 0) {

double1 = a + b;

label.setText(double1.toString());

sBuilder = new StringBuilder();

sBuilder.append(double1);

} else if (i == 1) {

double1 = a - b;

label.setText(double1.toString());

sBuilder = new StringBuilder();

sBuilder.append(double1);

} else if (i == 2) {

double1 = a * b;

label.setText(double1.toString());

sBuilder = new StringBuilder();

sBuilder.append(double1);

} else if (i == 3) {

double1 = a / b;

label.setText(double1.toString());

sBuilder = new StringBuilder();

sBuilder.append(double1);

} else {

label.setText(sBuilder.toString());

}

}

}

});

buttondecimal.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

sBuilder.append(".");

label.setText(sBuilder.toString());

}

});

buttonclear.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

sBuilder = new StringBuilder();

label.setText("");

}

});

buttondelet.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

if (!"".equals(sBuilder.toString())) {

sBuilder.deleteCharAt(sBuilder.length() - 1);

label.setText(sBuilder.toString());

}

}

});

this.setVisible(true);

}

public static void main(String[] args) {

new CaculatorDemo();

}

}

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版权声明：本文为CSDN博主「散人陈某」的原创文章，遵循 CC 4.0 BY-SA 版权协议，转载请附上原文出处链接及本声明。

原文链接：

java 计算器代码

import javax.swing.*;

import javax.swing.border.Border;

import java.awt.*;

import java.awt.event.ActionListener;

import java.awt.event.ActionEvent;

import java.math.BigDecimal;

import java.math.RoundingMode;

import java.util.HashMap;

/**

* 我的计算器。Cheshi 继承于 JFrame，是计算器的界面

c*/

public class Cheshi extends JFrame {

private Border border = BorderFactory.createEmptyBorder(5, 5, 5, 5);

private JTextField textbox = new JTextField("0");

private CalculatorCore core = new CalculatorCore();

private ActionListener listener = new ActionListener() {

public void actionPerformed(ActionEvent e) {

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

String label = b.getText();

String result = core.process(label);

textbox.setText(result);

}

};

public Cheshi(String title) throws HeadlessException {

super(title); // 调用父类构造方法

setupFrame(); // 调整窗体属性

setupControls(); // 创建控件

}

private void setupControls() {

setupDisplayPanel(); // 创建文本面板

setupButtonsPanel(); // 创建按钮面板

}

// 创建按钮面板并添加按钮

private void setupButtonsPanel() {

JPanel panel = new JPanel();

panel.setBorder(border);

panel.setLayout(new GridLayout(4, 5, 3, 3));

createButtons(panel, new String[]{

"7", "8", "9", "+", "C",

"4", "5", "6", "-", "CE",

"1", "2", "3", "*", "", // 空字符串表示这个位置没有按钮

"0", ".", "=", "/", ""

});

this.add(panel, BorderLayout.CENTER);

}

/**

* 在指定的面板上创建按钮

*

* @param panel 要创建按钮的面板

* @param labels 按钮文字

*/

private void createButtons(JPanel panel, String[] labels) {

for (String label : labels) {

// 如果 label 为空，则表示创建一个空面板。否则创建一个按钮。

if (label.equals("")) {

panel.add(new JPanel());

} else {

JButton b = new JButton(label);

b.addActionListener(listener); // 为按钮添加侦听器

panel.add(b);

}

}

}

// 设置显示面板，用一个文本框来作为计算器的显示部分。

private void setupDisplayPanel() {

JPanel panel = new JPanel();

panel.setLayout(new BorderLayout());

panel.setBorder(border);

setupTextbox();

panel.add(textbox, BorderLayout.CENTER);

this.add(panel, BorderLayout.NORTH);

}

// 调整文本框

private void setupTextbox() {

textbox.setHorizontalAlignment(JTextField.RIGHT); // 文本右对齐

textbox.setEditable(false); // 文本框只读

textbox.setBackground(Color.white); // 文本框背景色为白色

}

// 调整窗体

private void setupFrame() {

this.setDefaultCloseOperation(EXIT_ON_CLOSE); // 当窗体关闭时程序结束

this.setLocation(100, 50); // 设置窗体显示在桌面上的位置

this.setSize(300, 200); // 设置窗体大小

this.setResizable(false); // 窗体大小固定

}

// 程序入口

public static void main(String[] args) throws Exception {

UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());

Cheshi frame = new Cheshi("我的计算器");

frame.setVisible(true); // 在桌面上显示窗体

}

}

/**

* 计算器核心逻辑。这个逻辑只能处理 1~2 个数的运算。

*/

class CalculatorCore {

private String displayText = "0"; // 要显示的文本

boolean reset = true;

private BigDecimal number1, number2;

private String operator;

private HashMapString, Operator operators = new HashMapString, Operator();

private HashMapString, Processor processors = new HashMapString, Processor();

CalculatorCore() {

setupOperators();

setupProcessors();

}

// 为每种命令添加处理方式

private void setupProcessors() {

processors.put("[0-9]", new Processor() {

public void calculate(String command) {

numberClicked(command);

}

});

processors.put("\\.", new Processor() {

public void calculate(String command) {

dotClicked();

}

});

processors.put("=", new Processor() {

public void calculate(String command) {

equalsClicked();

}

});

processors.put("[+\\-*/]", new Processor() {

public void calculate(String command) {

operatorClicked(command);

}

});

processors.put("C", new Processor() {

public void calculate(String command) {

clearClicked();

}

});

processors.put("CE", new Processor() {

public void calculate(String command) {

clearErrorClicked();

}

});

}

// 为每种 operator 添加处理方式

private void setupOperators() {

operators.put("+", new Operator() {

public BigDecimal process(BigDecimal number1, BigDecimal number2) {

return number1.add(number2);

}

});

operators.put("-", new Operator() {

public BigDecimal process(BigDecimal number1, BigDecimal number2) {

return number1.subtract(number2);

}

});

operators.put("*", new Operator() {

public BigDecimal process(BigDecimal number1, BigDecimal number2) {

return number1.multiply(number2);

}

});

operators.put("/", new Operator() {

public BigDecimal process(BigDecimal number1, BigDecimal number2) {

return number1.divide(number2, 30, RoundingMode.HALF_UP);

}

});

}

// 根据命令处理。这里的命令实际上就是按钮文本。

public String process(String command) {

for (String pattern : processors.keySet()) {

if (command.matches(pattern)) {

processors.get(pattern).calculate(command);

break;

}

}

return displayText;

}

// 当按下 CE 时

private void clearErrorClicked() {

if (operator == null) {

number1 = null;

} else {

number2 = null;

}

displayText = "0";

reset = true;

}

// 当按下 C 时，将计算器置为初始状态。

private void clearClicked() {

number1 = null;

number2 = null;

operator = null;

displayText = "0";

reset = true;

}

// 当按下 = 时

private void equalsClicked() {

calculateResult();

number1 = null;

number2 = null;

operator = null;

reset = true;

}

// 计算结果

private void calculateResult() {

number2 = new BigDecimal(displayText);

Operator oper = operators.get(operator);

if (oper != null) {

BigDecimal result = oper.process(number1, number2);

displayText = result.toString();

}

}

// 当按下 +-*/ 时（这里也可以扩展成其他中间操作符）

private void operatorClicked(String command) {

if (operator != null) {

calculateResult();

}

number1 = new BigDecimal(displayText);

operator = command;

reset = true;

}

// 当按下 . 时

private void dotClicked() {

if (displayText.indexOf(".") == -1) {

displayText += ".";

} else if (reset) {

displayText = "0.";

}

reset = false;

}

// 当按下 0-9 时

private void numberClicked(String command) {

if (reset) {

displayText = command;

} else {

displayText += command;

}

reset = false;

}

// 运算符处理接口

interface Operator {

BigDecimal process(BigDecimal number1, BigDecimal number2);

}

// 按钮处理接口

interface Processor {

void calculate(String command);

}

}