Question

用java写的电脑附件中计算器的源代码

哪位大侠有
界面要像电脑中的计算器一样 不过只要实现标准型界面中的功能

Answer 1

package mycode;

import java.awt.*;

import java.awt.event.*;

import javax.swing.*;

public class Calculator extends JFrame{

static private int MAX_NUMBER_LENGTH = 21;

static private int PRIORITY_HIGHEST = 10;

static private int PRIORITY_HIGHER = 9;

static private int PRIORITY_HIGH = 6;

static private int PRIORITY_MIDDLE = 5;

static private int PRIORITY_LOW= 4;

static private int PRIORITY_LOWER = 2;

static private int PRIORITY_LOWEST = 1;

private JTextField t_result; //显示栏

private JPanel p_main; //盛放所有按钮的面板

private JPanel p_num; //数字按钮面板

private JPanel p_oper; //运算符按钮面板

private JPanel p_show; //

private JButton b_num[]; //数字按钮

private JButton b_oper[]; //运算符按钮

/**

* 构造函数

*/

public Calculator(){

super("Calculator");

t_result = new JTextField(" 0.0", MAX_NUMBER_LENGTH);

t_result.setEditable(false);

t_result.setBorder(BorderFactory.createLineBorder(Color.BLUE,3));

p_show = new JPanel();

p_main = new JPanel();

p_num = new JPanel();

p_oper = new JPanel();

p_show.add(t_result);

p_main.setLayout(new BorderLayout());

p_num.setLayout(new GridLayout(4, 3, 1, 1));

p_oper.setLayout(new GridLayout(4, 3, 1, 1));

//数字按钮

b_num = new JButton[12];

for(int i=0; i<10; i++)

b_num[i] = new JButton(new Integer(i+1).toString());

b_num[9] = new JButton("0");

b_num[10] = new JButton("cls");

b_num[11] = new JButton(".");

//操作符按钮

b_oper = new JButton[8];

b_oper[0] = new JButton("+");

b_oper[1] = new JButton("-");

b_oper[2] = new JButton("*");

b_oper[3] = new JButton("/");

b_oper[4] = new JButton("pow");

b_oper[5] = new JButton("sqrt");

b_oper[6] = new JButton("+/-");

b_oper[7] = new JButton("=");

//将按钮放入面板

for(int i=0; i<12; i++)

p_num.add(b_num[i]);

for(int i=0; i<8; i++)

p_oper.add(b_oper[i]);

Container contentPane = getContentPane();

contentPane.add(t_result, BorderLayout.NORTH);

contentPane.add(p_num, BorderLayout.WEST);

contentPane.add(p_oper, BorderLayout.EAST);

//初始化

setSize(400, 400);

setResizable(false);

pack();

setVisible(true);

//注册监听器

ButtonListener bl = new ButtonListener();

for(int i=0; i<12; i++)

b_num[i].addActionListener(bl);

for(int i=0; i<8; i++)

b_oper[i].addActionListener(bl);

}//end constructor

class ButtonListener implements ActionListener{

// 内部类ButtonListener继承ActionListener响应按钮

private String lastOp; //记录前一个运算符

private String strVal; //字符化的计算数值

private double number; //新输入或临时存放数值

private double total; //记录计算数值

private boolean opPressed; //判断operator是否按下

private double numStack[]; //数字堆栈

private String operStack[]; //符号堆栈

private int numPoint; //数字堆栈指针

private int operPoint; //符号堆栈指针

ButtonListener(){

numStack = new double[MAX_NUMBER_LENGTH/2];

operStack = new String[MAX_NUMBER_LENGTH/2];

numPoint = 0;

operPoint = 0;

opPressed = false;

strVal = "";

number = 0.0;

total = 0.0;

System.out.println("construtor!!");

}

//用于检查Error的函数，查看各个参数的值

void checkValues(){

System.out.println("| --------Values check out----------------");

System.out.println("| opPressed: " + opPressed);

System.out.println("| lastOp: " + lastOp);

System.out.println("| strVal: " + strVal);

System.out.println("| number: " + number);

System.out.println("| total: " + total);

System.out.println("| ----------------------------------------");

}

public void actionPerformed(ActionEvent ae){

String s = ((JButton)ae.getSource()).getActionCommand().trim();

if( Character.isDigit(s.charAt(0)) )

handleNumber(s);

else

calculate(s);

}

/*

* 处理数字

* */

void handleNumber(String s){

if( !opPressed ){ //没按下运算符按钮则为数字

strVal += s;

t_result.setText(strVal);

checkValues();

}

else{

//当按下运算符时，清除strVal并存入新输入数值的第一个数值

opPressed = false;

//lastOp = null;

strVal = s;

t_result.setText(strVal);

checkValues();

}

}

/**/

boolean isUnaryOp(String op){

return ( op.equals("sqrt") || op.equals("=") ||op.equals("cls") ||

op.equals("+/-") || op.equals("."));

}

/*运算符等级

* 一元运算符 +/-，= ，.,sqrt， cls 为1级

* 二元中pow为2级，*，/为3级，+，-为4级

* */

int operatorPriorityLevel( String op ){

int opPriLevel;

if(isUnaryOp(op)){

opPriLevel = PRIORITY_HIGHEST;

}

else {

if(op.equals("pow")){

opPriLevel = PRIORITY_HIGHER;

}

else {

if(op.equals("*") || op.equals("/")){

opPriLevel = PRIORITY_MIDDLE;

}

else //if(op.equals("+") || op.equals("-"))

{

opPriLevel = PRIORITY_LOW;

}

}

}

return opPriLevel;

}

/* 运算符包括一元(UnaryOp)和二元(BinaryOp)

一元有sqrt，cls，=，+/-,.(小数点)

二元有+，-，*，/，pow

*/

void calculate(String op){

opPressed = true; //运算符被按下

number = getNumberOnDisplay(); //将新输入的数由显示器上的转存入number

if(isUnaryOp(op))

handleUnaryOp(op);

else

handleBinaryOp(op);

}

void handleDecPoint(){

opPressed = false; //事实上小数点不算运算符，在这里我把它作为一种特殊的符号处理

if( strVal.indexOf(".")<0 ){

strVal += ".";

}

t_result.setText(strVal);

checkValues();

}

/* =号较为特殊，且用的频率较高

如果有=号，意味着一次预算的结束

所以opPressed要清零

*/

void handleUnaryOp( String op ){

if( op.equals("=") ){ //处理=号的情况

//如果前一预算符是二元运算符

if(lastOp.equals("+"))

total += number;

else if(lastOp.equals("-"))

total -= number;

else if(lastOp.equals("*"))

total *= number;

else if(lastOp.equals("/")){

try{

total /= number;

}catch(ArithmeticException ae){

//除0错误！！

t_result.setText("Error!");

}

}

else if(lastOp.equals("pow")){

total = Math.pow(total, number);

}

if(operPoint == 0){

strVal = new Double(total).toString();

t_result.setText(strVal);

opPressed = false;

numPoint = 0;

operPoint = 0;

lastOp = null;

}

else{ //堆栈中还有压有运算符

number = total;

lastOp = operStack[--operPoint];

total = numStack[--numPoint];

calculate(op);

}

checkValues();

}//end if op.equals("=")

else if( op.equals("sqrt") ){ //处理sqrt的情况

number = Math.sqrt(number);

strVal = new Double(number).toString();

t_result.setText(strVal);

}

else if(op.equals("+/-")){ //处理+/-的情况

number = -number;

strVal = new Double(number).toString().trim();

t_result.setText(strVal);

}

else if(op.equals(".")){ //处理小数点

checkValues();

handleDecPoint();

}

else if(op.equals("cls")){ //清盘处理！

clear();

}

checkValues();

}

void handleBinaryOp(String op){

//计算二元运算符并且opPressed=true

if(lastOp != null){

//前面有运算符

if(operatorPriorityLevel(lastOp) > operatorPriorityLevel(op)

|| operatorPriorityLevel(lastOp) == operatorPriorityLevel(op)){

//前一个运算符优先级大于或等于现在的

if( lastOp.equals("+") )

total += number;

else if(lastOp.equals("-"))

total -= number;

else if(lastOp.equals("*"))

total *= number;

else if(lastOp.equals("/")){

try{

total /= number;

}catch(ArithmeticException ae){

//除0错误！！

t_result.setText("Error!");

}

}

else if(lastOp.equals("pow")){

total = Math.pow(total, number);

}

number = total;

if(operPoint != 0){ //堆栈中还有压有运算符

lastOp = operStack[--operPoint];

total = numStack[--numPoint];

calculate(op);

}

strVal = (new Double(total)).toString().trim();

t_result.setText(strVal);

lastOp = op;

}

else{//现行运算符优先级高

numStack[numPoint++] = total;

operStack[operPoint++] = lastOp;

total = number;

lastOp = op; //前一运算符压入堆栈所以没lastOp

//calculate(op);

}

} //end

else{

if(operPoint != 0){

lastOp = operStack[--operPoint];

total = numStack[--numPoint];

calculate(op);

}

else{//lastOp = null && operPoint == 0) 即为第一个符号

total = number;

lastOp = op;

}

}

checkValues();

}

void clear(){

numPoint = 0;

operPoint = 0;

opPressed = false;

number = 0.0;

total = 0.0;

strVal = "";

lastOp = null;

t_result.setText(" 0.0");

checkValues();

}

double getNumberOnDisplay(){

return new Double(strVal.trim()).doubleValue();

}

}

public static void main(String args[]){

new Calculator();

}

}