简易计算器第一版

public class Main {public static void main(String[] args) {MyFrame frame= new MyFrame("曙光一号");frame.setVisible(true);}}

界面如下图：

import java.awt.Color;import java.awt.Font;import java.awt.GridLayout;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.math.BigDecimal;import javax.swing.JButton;import javax.swing.JFrame;import javax.swing.JLabel;import javax.swing.JPanel;public class MyFrame extends JFrame implements ActionListener {private static final long serialVersionUID = 1L;// 设定最大长度！！！考虑负数！！！单目运算符多次操作！！！// .....String string_1 = "";// 第一个数String string_2 = "";// 符号String string_3 = "";// 第二个数String strings = "0";// 用来设置label(为string_1+string_2+string_3)boolean isNum_1Exist = false;// 第一个数是否存在boolean isNum_2Exist = false;// 第二个数是否存在boolean isSignExist = false;// 是否有运算符boolean isNum_1Point = false;// 第一个数是否有小数点boolean isNum_2Point = false;// 第二个数是否有小数点boolean isAlong = false;//单目运算JLabel label = new JLabel();JButton[] buttons = new JButton[20];public MyFrame(String string) {super(string);setBounds(450, 80, 300, 400);// 设置窗口位置大小setResizable(false);// 窗口不可变setDefaultCloseOperation(EXIT_ON_CLOSE);// 关闭操作，直接关闭setLayout(new GridLayout(6, 1));Font font = new Font(getName(), Font.BOLD, 35);/////////////////// 面板1/////////////////////JPanel panel_1 = new JPanel();label.setHorizontalAlignment(JLabel.RIGHT);label.setFont(new Font("楷体", ALLBITS, 15));panel_1.add(label);add(panel_1);/////////////////// 面板2/////////////////////JPanel panel_2 = new JPanel();panel_2.setLayout(new GridLayout(1, 4));panel_2.setBackground(Color.lightGray);panel_2.setFont(font);buttons[0] = new JButton("%");buttons[1] = new JButton("sqrt");buttons[2] = new JButton("^2");buttons[3] = new JButton("AC");for (int i = 0; i < 4; i++) {panel_2.add(buttons[i]);}add(panel_2);/////////////////// 面板3/////////////////////JPanel panel_3 = new JPanel();panel_3.setLayout(new GridLayout(1, 4));panel_3.setBackground(Color.lightGray);panel_3.setFont(font);buttons[4] = new JButton("7");buttons[5] = new JButton("8");buttons[6] = new JButton("9");buttons[7] = new JButton("+");for (int i = 4; i < 8; i++) {panel_3.add(buttons[i]);}add(panel_3);/////////////////// 面板4/////////////////////JPanel panel_4 = new JPanel();panel_4.setLayout(new GridLayout(1, 4));panel_4.setBackground(Color.lightGray);panel_4.setFont(font);buttons[8] = new JButton("4");buttons[9] = new JButton("5");buttons[10] = new JButton("6");buttons[11] = new JButton("-");for (int i = 8; i < 12; i++) {panel_4.add(buttons[i]);}add(panel_4);/////////////////// 面板5/////////////////////JPanel panel_5 = new JPanel();panel_5.setLayout(new GridLayout(1, 4));panel_5.setBackground(Color.lightGray);panel_5.setFont(font);buttons[12] = new JButton("1");buttons[13] = new JButton("2");buttons[14] = new JButton("3");buttons[15] = new JButton("*");for (int i = 12; i < 16; i++) {panel_5.add(buttons[i]);}add(panel_5);/////////////////// 面板6/////////////////////JPanel panel_6 = new JPanel();panel_6.setLayout(new GridLayout(1, 4));panel_6.setBackground(Color.lightGray);panel_6.setFont(font);buttons[16] = new JButton("0");buttons[17] = new JButton(".");buttons[18] = new JButton("=");buttons[19] = new JButton("/");for (int i = 16; i < 20; i++) {panel_6.add(buttons[i]);}add(panel_6);// 添加监听for (int i = 0; i < buttons.length; i++) {buttons[i].addActionListener(this);}}@Overridepublic void actionPerformed(ActionEvent e) {if (e.getSource() == buttons[3]) {// ACremove();}//////////////// 符号/////////////////if (isNum_1Exist) {// 单目运算不需要按等号if (e.getSource() == buttons[1] && isNum_1Exist) {// sqrtdouble i = Double.parseDouble(string_1);double s = Math.sqrt(i);String string = "" + s;label.setText(string);string_1 = string;isNum_1Exist = true;isAlong = true;} else if (e.getSource() == buttons[2] && isNum_1Exist) {// ^2double i = Double.parseDouble(string_1);i = i * i;String string = "" + i;label.setText(string);string_1 = string;isNum_1Exist = true;isAlong = true;} else if (e.getSource() == buttons[0]) {// %setDual("%");} else if (e.getSource() == buttons[7]) {// +setDual("+");} else if (e.getSource() == buttons[11]) {// -setDual("-");} else if (e.getSource() == buttons[15]) {// *setDual("*");} else if (e.getSource() == buttons[19]) {// /setDual("/");} else if (e.getSource() == buttons[18]) {// =// 计算：String str = count();// 清空数据remove();label.setText(str);}}/////////////// 数字//////////////// 第一个数没有 或者 有了第一个数还没有符号 就加到第一个数if (e.getSource() == buttons[4]) {// 7setNum("7");} else if (e.getSource() == buttons[5]) {// 8setNum("8");} else if (e.getSource() == buttons[6]) {// 9setNum("9");} else if (e.getSource() == buttons[8]) {// 4setNum("4");} else if (e.getSource() == buttons[9]) {// 5setNum("5");} else if (e.getSource() == buttons[10]) {// 6setNum("6");} else if (e.getSource() == buttons[12]) {// 1setNum("1");} else if (e.getSource() == buttons[13]) {// 2setNum("2");} else if (e.getSource() == buttons[14]) {// 3setNum("3");} else if (e.getSource() == buttons[16]) {// 0setNum("0");} else if (e.getSource() == buttons[17]) {// .// 一个数只能有一个if ((!isNum_1Exist) || (isNum_1Exist && !isSignExist)) {// 1if (!isNum_1Point) {setNum1(".");isNum_1Point = true;}} else {// 2if (!isNum_2Point)setNum2(".");isNum_2Point = true;}}}// 计算(双目)// 结果的label 在这里统一设置private String count() {try {BigDecimal b1 = new BigDecimal(string_1);BigDecimal b2 = new BigDecimal(string_3);switch (string_2) {case "+":BigDecimal b = b1.add(b2);strings = b.toString();break;case "-":b = b1.subtract(b2);strings = b.toString();break;case "*":b = b1.multiply(b2);strings = b.toString();break;case "/":if (!(string_3.equals("0"))) {b = b1.divide(b2);strings = b.toString();}else {strings = "除数不能为零";}break;case "%":b = b1.remainder(b2);strings = b.toString();break;default:}} catch (Exception e) {}return strings;}private void setDual(String s) {// 双目运算：第一个数存在，第二个数还不存在的是时候可以加符号// 否则如果两个都存在了就相当于等号(执行运算方法！！)if (isNum_1Exist && !isNum_2Exist) {string_2 = s;isSignExist = true;strings = string_1 + string_2;label.setText(strings);} else if (isNum_1Exist && isNum_2Exist) {String str = count();remove();string_1 = str;isNum_1Exist = true;string_2 = s;isSignExist = true;strings = string_1 + string_2;label.setText(strings);}}private void remove() {label.setText("");isNum_1Exist = false;isNum_2Exist = false;isSignExist = false;isNum_1Point = false;isNum_2Point = false;string_1 = "";string_2 = "";string_3 = "";}private void setNum(String s) {if(isAlong){string_1 = "";isNum_1Exist = false;isAlong = false;}if ((!isNum_1Exist) || (isNum_1Exist && !isSignExist)) {// 1setNum1(s);} else {// 2setNum2(s);}}private void setNum1(String s) {string_1 += s;isNum_1Exist = true;label.setText(string_1);}private void setNum2(String s) {string_3 += s;isNum_2Exist = true;strings = string_1 + string_2 + string_3;label.setText(strings);}}