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C++结合QT实现带有优先级的计算器功能

2021-10-18 14:20ruokey_1 C/C++

这篇文章主要介绍了C++结合QT实现带有优先级的计算器,本文通过实例代码给大家介绍的非常详细，对大家的学习或工作具有一定的参考借鉴价值，需要的朋友可以参考下

代码

MyCalculator.h

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#pragma once
 
#include <QtWidgets/QMainWindow>
#include <QStack>
#include <QString>
#include "ui_MyCalculator.h"
 
class MyCalculator : public QMainWindow
{
  Q_OBJECT
 
public:
  MyCalculator(QWidget *parent = Q_NULLPTR);
    
/*  void setnum1(int num);
    void setnum2(int num);
    void setflag(int f);
    int calculartor();
*/
 
 
private slots:
    void on_number_Button_clicked();
    void on_action_Button_clicked();
    void on_comma_Button_clicked();
    void on_action_Button_c_clicked();
    void on_action_Button_d_clicked();
    void on_action_Button_e_clicked();
 
/*
    void on_action_Button_equal_clicked();
    void on_number_Button_clicked();
    void on_action_Button_clicked();
    void on_action_Button_c_clicked();
*/
 
private:
  Ui::MyCalculatorClass ui;
 
};

MyCalculator.main

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#include "MyCalculator.h"
#include <QtWidgets/QApplication>
 
int main(int argc, char *argv[])
{
  QApplication a(argc, argv);
  MyCalculator w;
  w.show();
  return a.exec();
}

MyCalculator.cpp

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#include "MyCalculator.h"
 
#include<iostream>
using namespace std;
#include<stack>
#include<vector>
#include<cstdlib>
#include<limits.h>
 
MyCalculator::MyCalculator(QWidget *parent)
  : QMainWindow(parent)
{
  ui.setupUi(this);
    setWindowTitle(QStringLiteral("计算器"));
    ui.textBrowser->setFontPointSize(28);
 
    connect(ui.pushButton0, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));
    connect(ui.pushButton1, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));
    connect(ui.pushButton2, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));
    connect(ui.pushButton3, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));
    connect(ui.pushButton4, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));
    connect(ui.pushButton5, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));
    connect(ui.pushButton6, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));
    connect(ui.pushButton7, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));
    connect(ui.pushButton8, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));
    connect(ui.pushButton9, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));
 
    connect(ui.pushButton_add, SIGNAL(clicked()), this, SLOT(on_action_Button_clicked()));
    connect(ui.pushButton_div, SIGNAL(clicked()), this, SLOT(on_action_Button_clicked()));
    connect(ui.pushButton_mul, SIGNAL(clicked()), this, SLOT(on_action_Button_clicked()));
    connect(ui.pushButton_sub, SIGNAL(clicked()), this, SLOT(on_action_Button_clicked()));
    connect(ui.pushButton_right, SIGNAL(clicked()), this, SLOT(on_action_Button_clicked()));
    connect(ui.pushButton_left, SIGNAL(clicked()), this, SLOT(on_action_Button_clicked()));
    connect(ui.pushButton_dian, SIGNAL(clicked()), this, SLOT(on_comma_Button_clicked()));
 
 
    connect(ui.pushButton_del, SIGNAL(clicked()), this, SLOT(on_action_Button_d_clicked()));
    connect(ui.pushButton_re, SIGNAL(clicked()), this, SLOT(on_action_Button_c_clicked()));
    connect(ui.pushButton_equ, SIGNAL(clicked()), this, SLOT(on_action_Button_e_clicked()));
    /*
    //没有优先级的计算器
    connect(ui.pushButton0, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));
    connect(ui.pushButton1, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));
    connect(ui.pushButton2, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));
    connect(ui.pushButton3, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));
    connect(ui.pushButton4, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));
    connect(ui.pushButton5, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));
    connect(ui.pushButton6, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));
    connect(ui.pushButton7, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));
    connect(ui.pushButton8, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));
    connect(ui.pushButton9, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));
 
    connect(ui.pushButton_add, SIGNAL(clicked()), this, SLOT(on_action_Button_clicked()));
    connect(ui.pushButton_div, SIGNAL(clicked()), this, SLOT(on_action_Button_clicked()));
    connect(ui.pushButton_mul, SIGNAL(clicked()), this, SLOT(on_action_Button_clicked()));
    connect(ui.pushButton_sub, SIGNAL(clicked()), this, SLOT(on_action_Button_clicked()));
 
    connect(ui.pushButton_re, SIGNAL(clicked()), this, SLOT(on_action_Button_c_clicked()));
 
    connect(ui.pushButton_equ, SIGNAL(clicked()), this, SLOT(on_action_Button_equal_clicked()));
    */
 
}
void MyCalculator::on_number_Button_clicked()
{
    QPushButton *btn = qobject_cast<QPushButton*>(sender());
    QString number = btn->text();
    QString ss = ui.textBrowser->toPlainText();
    ui.textBrowser->clear();
    ui.textBrowser->append(ss + number);
}
void MyCalculator::on_action_Button_clicked()//操作符
{
    QPushButton *btn = qobject_cast<QPushButton*>(sender());
    QString action = btn->text();
    QString ss = ui.textBrowser->toPlainText();
    ui.textBrowser->clear();
    ui.textBrowser->append(ss + action);
}
void MyCalculator::on_comma_Button_clicked()//小数点
{
    QPushButton *btn = qobject_cast<QPushButton*>(sender());
    QString action = btn->text();
    QString ss = ui.textBrowser->toPlainText();
    ui.textBrowser->clear();
    ui.textBrowser->append(ss + action);
}
void MyCalculator::on_action_Button_c_clicked()//重置输入框里的内容
{
    ui.textBrowser->clear();
}
void MyCalculator::on_action_Button_d_clicked()//删除表达式中最后一个符号
{
    QString ss = ui.textBrowser->toPlainText();//在一行
    ss = ss.left(ss.length() - 1);
    ui.textBrowser->clear();
    ui.textBrowser->setText(ss);
}
bool isNum(QString ch)
{
    if (ch >= '0' && ch <= '9' || ch == '.')
        return true;
    else
        return false;
}
bool isOperate(QString ch)
{
    if (ch == '+' || ch == '-' || ch == '*' || ch == '/' || ch == '(' || ch == ')' )
        return true;
    else
        return false;
}
int level(QString ch) {//优先级设置
    if(ch == '(')
        return 5;
    else if (ch == '*' || ch== '/')
        return 4;
    else if (ch == '+' || ch == '-')
        return 3;
    else if (ch == ')')
        return 2;
}
double calcu(double a ,double b, QString c)
{
    double result = 0;
    if (c == '+')
        result = b + a;
    else if (c == '-')
        result = b - a;
    else if (c == '*')
        result = b * a;
    else if (c == '/')
        result = b / a;
    else
        result = INT_MAX;
    return result;
}
double getjieguo(QString input)
{
    QStack<double> Num;
    QStack<QString> Act;
    int a = input.length();
    for(int i=0;i< a;i++)
    {
        int flag = 0;//用来判断是否是数字
        int xiaoshu = 1;//用来判断是否是小数部分
        double number = 0;//暂存数字
        QString frist = input.left(1);
        while (isNum(frist))                //连续的数字转化为一个整数
        {
            if (frist == '.' || xiaoshu == 2)
            {
                number = frist.toDouble() / 10 + number;
                xiaoshu = 2;
            }
            else
            {
                number = number * 10 + frist.toInt();
            }
            input = input.right(input.length() - 1);
            frist = input.left(1);
            flag = 1;
        }
        if (flag == 1)
            Num.push(number);
 
        if (isOperate(frist))
        {
            if (!Act.empty() && (level(Act.top()) > level(frist)))
            {
                    double a = Num.pop();
                    double b = Num.pop();
                    QString c = Act.pop();
                    double result = calcu(a, b, c);
                    Num.push(result);
                    if (frist != ')')
                        Act.push(frist);
                    input = input.right(input.length() - 1);
                    frist = input.left(1);
            }
            else if (!Act.empty() && (level(Act.top()) <= level(frist)))
            {
                if (frist != '(')
                    Act.push(frist);
                input = input.right(input.length() - 1);
                frist = input.left(1);
            }
            else if(Act.empty())                //操作符第一次入符号栈
            {
                Act.push(frist);
                input = input.right(input.length() - 1);
                frist = input.left(1);
            }
        }
        if (frist == '=')//支持得到结果后仍可以继续运算
        {
            Num.clear();
            Act.clear();
            input = input.right(input.length() - 1);
            frist = input.left(1);
        }
 
        if (i + 1 >= a)              //当表达式都进栈后，只要符号栈不为空就继续执行
        {
            while (!Act.empty())
            {
                double a1 = Num.pop();
                double b1 = Num.pop();
                QString c1 = Act.pop();
                double result = calcu(a1, b1, c1);
                Num.push(result);
            }
        }
    }
 
    return Num.top();
 
}
void MyCalculator::on_action_Button_e_clicked()
{
    QString input = ui.textBrowser->toPlainText();//将输入框里的内容给input
    double value = getjieguo(input);//将表达式传给getjieguo来将数字和操作符分别入对应的栈
    ui.textBrowser->clear();
    ui.textBrowser->append(input + "=" + QString::number(value));//将结果的类型由数字转化为QString
 
}
/*
void MyCalculator::setnum1(int num)
{
    num1 = num;
}
void MyCalculator::setnum2(int num)
{
    num2 = num;
}
void MyCalculator::setflag(int f)
{
    flag = f;
}
int MyCalculator::calculartor()
{
    int result = 0;
    if (flag == 1)
        result = num1 + num2;
    else if (flag == 2)
        result = num1 - num2;
    else if (flag == 3)
        result = num1 * num2;
    else if (flag == 4)
    {
        if (num2 == 0)
            setflag(5);
        else
            result = num1 / num2;
    }
    else
        result = 0;
 
    return result;
}
 
void MyCalculator::on_action_Button_c_clicked()
{
    ui.textBrowser->clear();
    setnum1(0);
    setnum2(0);
    setflag(0);
}
 
void MyCalculator::on_number_Button_clicked()
{
    QPushButton *btn = qobject_cast<QPushButton*>(sender());
    QString number = btn->text();
    QString ss = ui.textBrowser->toPlainText();
    ui.textBrowser->clear();
    ui.textBrowser->append(ss + number);
}
 
void MyCalculator::on_action_Button_clicked()
{
    int number = ui.textBrowser->toPlainText().toInt();
    setnum1(number);
    QPushButton *btn = qobject_cast<QPushButton*>(sender());
    QString action = btn->text();
    ui.textBrowser->clear();
    if (action == "+")
        setflag(1);
    else if (action == "-")
        setflag(2);
    else if (action == "*")
        setflag(3);
    else
        setflag(4);
 
}
 
void MyCalculator::on_action_Button_equal_clicked() {
    int number = ui.textBrowser->toPlainText().toInt();
    setnum2(number);
    int res = calculartor();
    ui.textBrowser->clear();
    if (flag == 5)
        ui.textBrowser->append(QStringLiteral("不能除于0，请重新输入"));
    else
        ui.textBrowser->append(QString::number(res));
}
*/

测试

 

表达式 结果
2*3+6-(1+3) 8
2+3*6-(1+3) 16
2+3*6-(1.3+5/2) 16.2

 

说明

  1. 自己的学习笔记 ，还有一些bug没有解决；
  2. 部分代码需要优化，重构；
  3. 没有实现输入错误表达式报错功能，需要输入正确的表达式。
  4. 不支持负数计算。
  5. 支持小数，加，减，乘，除，括号运算。

C++结合QT实现带有优先级的计算器功能

到此这篇关于C++结合QT实现带有优先级的计算器的文章就介绍到这了,更多相关C++实现计算器内容请搜索服务器之家以前的文章或继续浏览下面的相关文章希望大家以后多多支持服务器之家！

原文链接：https://blog.csdn.net/qq_44052058/article/details/112170541

  • 计算器
  • Qt
  • C++

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