java计算器

冷不防 2022-12-17 08:47 154阅读 0赞

import java.awt.*;
    import java.awt.event.*;
    import javax.swing.*;
    import java.util.Vector;
    import java.math.BigDecimal;
    
    public class Calculator {
    
        // 操作数1，为了程序的安全，初值一定设置，这里我们设置为0。
        String str1 = "0";
    
        // 操作数2
        String str2 = "0";
    
        // 运算符
        String signal = "+";
    
        // 运算结果
        String result = "";
    
        // 以下k1至k2为状态开关
    
        // 开关1用于选择输入方向，将要写入str1或str2
        int k1 = 1;
        // 开关2用于记录符号键的次数，如果 k2>1 说明进行的是 2+3-9+8 这样的多符号运算
        int k2 = 1;
        // 开关3用于标识 str1 是否可以被清0 ，等于1时可以，不等于1时不能被清0
        int k3 = 1;
        // 开关4用于标识 str2 是否可以被清0
        int k4 = 1;
        // 开关5用于控制小数点可否被录入，等于1时可以，不为1时，输入的小数点被丢掉
        int k5 = 1;
        // store的作用类似于寄存器，用于记录是否连续按下符号键
        JButton store;
    
        @SuppressWarnings("rawtypes")
        Vector vt = new Vector(20, 10);
    
        // 声明各个UI组件对象并初始化
        JFrame frame = new JFrame("Calculator");
        JTextField result_TextField = new JTextField(result, 20);
        JButton clear_Button = new JButton("Clear");
        JButton button0 = new JButton("0");
        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 button_Dian = new JButton(".");
        JButton button_jia = new JButton("+");
        JButton button_jian = new JButton("-");
        JButton button_cheng = new JButton("*");
        JButton button_chu = new JButton("/");
        JButton button_dy = new JButton("=");
    
        // 计算机类的构造器
        public Calculator() {
    
            // 为按钮设置等效键，即可以通过对应的键盘按键来代替点击它
            button0.setMnemonic(KeyEvent.VK_0);
            // 其它等效键省略，你可以自行补充完整
    
            // 设置文本框为右对齐，使输入和结果都靠右显示
            result_TextField.setHorizontalAlignment(JTextField.RIGHT);
    
            // 将UI组件添加进容器内
            JPanel pan = new JPanel();
            pan.setLayout(new GridLayout(4, 4, 5, 5));
            pan.add(button7);
            pan.add(button8);
            pan.add(button9);
            pan.add(button_chu);
            pan.add(button4);
            pan.add(button5);
            pan.add(button6);
            pan.add(button_cheng);
            pan.add(button1);
            pan.add(button2);
            pan.add(button3);
            pan.add(button_jian);
            pan.add(button0);
            pan.add(button_Dian);
            pan.add(button_dy);
            pan.add(button_jia);
            pan.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
    
            JPanel pan2 = new JPanel();
            pan2.setLayout(new BorderLayout());
            pan2.add(result_TextField, BorderLayout.WEST);
            pan2.add(clear_Button, BorderLayout.EAST);
    
            // 设置主窗口出现在屏幕上的位置
            frame.setLocation(300, 200);
            // 设置窗体不能调大小
            frame.setResizable(false);
            frame.getContentPane().setLayout(new BorderLayout());
            frame.getContentPane().add(pan2, BorderLayout.NORTH);
            frame.getContentPane().add(pan, BorderLayout.CENTER);
    
            frame.pack();
            frame.setVisible(true);
    
            // 事件处理程序
    
            // 数字键
            class Listener implements ActionListener {
                @SuppressWarnings("unchecked")
                public void actionPerformed(ActionEvent e) {
                    String ss = ((JButton) e.getSource()).getText();
                    store = (JButton) e.getSource();
                    vt.add(store);
                    if (k1 == 1) {
                        if (k3 == 1) {
                            str1 = "";
    
                            // 还原开关k5状态
                            k5 = 1;
                        }
                        str1 = str1 + ss;
    
                        k3 = k3 + 1;
    
                        // 显示结果
                        result_TextField.setText(str1);
    
                    } else if (k1 == 2) {
                        if (k4 == 1) {
                            str2 = "";
    
                            // 还原开关k5状态
                            k5 = 1;
                        }
                        str2 = str2 + ss;
                        k4 = k4 + 1;
                        result_TextField.setText(str2);
                    }
    
                }
            }
    
            // 输入的运算符号的处理
            class Listener_signal implements ActionListener {
                @SuppressWarnings("unchecked")
                public void actionPerformed(ActionEvent e) {
                    String ss2 = ((JButton) e.getSource()).getText();
                    store = (JButton) e.getSource();
                    vt.add(store);
    
                    if (k2 == 1) {
                        // 开关 k1 为 1 时向数 1 写输入值，为2时向数2写输入值。
                        k1 = 2;
                        k5 = 1;
                        signal = ss2;
                        k2 = k2 + 1;// 按符号键的次数
                    } else {
                        int a = vt.size();
                        JButton c = (JButton) vt.get(a - 2);
    
                        if (!(c.getText().equals("+")) && !(c.getText().equals("-")) && !(c.getText().equals("*"))
                                && !(c.getText().equals("/")))
    
                        {
                            cal();
                            str1 = result;
                            // 开关 k1 为 1 时，向数 1 写值，为2时向数2写
                            k1 = 2;
                            k5 = 1;
                            k4 = 1;
                            signal = ss2;
                        }
                        k2 = k2 + 1;
    
                    }
    
                }
            }
    
            // 清除键的逻辑（Clear）
            class Listener_clear implements ActionListener {
                @SuppressWarnings("unchecked")
                public void actionPerformed(ActionEvent e) {
                    store = (JButton) e.getSource();
                    vt.add(store);
                    k5 = 1;
                    k2 = 1;
                    k1 = 1;
                    k3 = 1;
                    k4 = 1;
                    str1 = "0";
                    str2 = "0";
                    signal = "";
                    result = "";
                    result_TextField.setText(result);
                    vt.clear();
                }
            }
    
            // 等于键的逻辑
            class Listener_dy implements ActionListener {
                @SuppressWarnings("unchecked")
                public void actionPerformed(ActionEvent e) {
    
                    store = (JButton) e.getSource();
                    vt.add(store);
                    cal();
    
                    // 还原各个开关的状态
                    k1 = 1;
                    k2 = 1;
                    k3 = 1;
                    k4 = 1;
    
                    str1 = result;
                }
            }
    
            // 小数点的处理
            class Listener_xiaos implements ActionListener {
                @SuppressWarnings("unchecked")
                public void actionPerformed(ActionEvent e) {
                    store = (JButton) e.getSource();
                    vt.add(store);
                    if (k5 == 1) {
                        String ss2 = ((JButton) e.getSource()).getText();
                        if (k1 == 1) {
                            if (k3 == 1) {
                                str1 = "";
                                // 还原开关k5状态
                                k5 = 1;
                            }
                            str1 = str1 + ss2;
    
                            k3 = k3 + 1;
    
                            // 显示结果
                            result_TextField.setText(str1);
    
                        } else if (k1 == 2) {
                            if (k4 == 1) {
                                str2 = "";
                                // 还原开关k5的状态
                                k5 = 1;
                            }
                            str2 = str2 + ss2;
    
                            k4 = k4 + 1;
    
                            result_TextField.setText(str2);
                        }
                    }
    
                    k5 = k5 + 1;
                }
            }
    
            // 注册各个监听器，即绑定事件响应逻辑到各个UI组件上
            Listener_dy jt_dy = new Listener_dy();
    
            // 监听数字键
            Listener jt = new Listener();
            // 监听符号键
            Listener_signal jt_signal = new Listener_signal();
            // 监听清除键
            Listener_clear jt_c = new Listener_clear();
            // 监听小数点键
            Listener_xiaos jt_xs = new Listener_xiaos();
    
            button7.addActionListener(jt);
            button8.addActionListener(jt);
            button9.addActionListener(jt);
            button_chu.addActionListener(jt_signal);
            button4.addActionListener(jt);
            button5.addActionListener(jt);
            button6.addActionListener(jt);
            button_cheng.addActionListener(jt_signal);
            button1.addActionListener(jt);
            button2.addActionListener(jt);
            button3.addActionListener(jt);
            button_jian.addActionListener(jt_signal);
            button0.addActionListener(jt);
            button_Dian.addActionListener(jt_xs);
            button_dy.addActionListener(jt_dy);
            button_jia.addActionListener(jt_signal);
            clear_Button.addActionListener(jt_c);
    
            // 窗体关闭事件的响应程序
            frame.addWindowListener(new WindowAdapter() {
                public void windowClosing(WindowEvent e) {
                    System.exit(0);
                }
            });
    
        }
    
        // 计算逻辑
        public void cal() {
            // 操作数1
            double a2;
            // 操作数2
            double b2;
            // 运算符
            String c = signal;
            // 运算结果
            double result2 = 0;
    
            if (c.equals("")) {
                result_TextField.setText("Please input operator");
    
            } else {
                // 手动处理小数点的问题
                if (str1.equals("."))
                    str1 = "0.0";
                if (str2.equals("."))
                    str2 = "0.0";
                a2 = Double.valueOf(str1).doubleValue();
                b2 = Double.valueOf(str2).doubleValue();
    
                if (c.equals("+")) {
                    result2 = a2 + b2;
                }
                if (c.equals("-")) {
                    result2 = a2 - b2;
                }
                if (c.equals("*")) {
                    BigDecimal m1 = new BigDecimal(Double.toString(a2));
                    BigDecimal m2 = new BigDecimal(Double.toString(b2));
                    result2 = m1.multiply(m2).doubleValue();
                }
                if (c.equals("/")) {
                    if (b2 == 0) {
                        result2 = 0;
                    } else {
                        result2 = a2 / b2;
                    }
    
                }
    
                result = ((new Double(result2)).toString());
    
                result_TextField.setText(result);
            }
        }
    
        @SuppressWarnings("unused")
        public static void main(String[] args) {
            // 设置程序显示的界面风格，可以去除
            try {
                UIManager.setLookAndFeel("javax.swing.plaf.metal.MetalLookAndFeel");
            } catch (Exception e) {
                e.printStackTrace();
            }
            Calculator cal = new Calculator();
        }
    
    }