Qt简易计算器的代码实现

 大二用qt写的简易计算机，已经修改完bug,请放心食用

输入的时候一定用按钮，不要直接在文本框中输入

在qt中新建这几个文件，运行就OK了

 main.cpp

 

#include "calculator.h"
#include 

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    calculator w;
    w.show();

    return a.exec();
}

 

 

 

calculator.h的代码

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include 
#include
#include
#include
#include
#include
#include
#include
#include
#include
class calculator : public QMainWindow
{
    Q_OBJECT

public:
    calculator(QWidget *parent = 0);
    ~calculator();

private:
      QLineEdit *inputLine;//显示框
      QString input="0"; //输入框
      bool flat=false;
      //0-9按钮
      QPushButton *zeroButton;
      QPushButton *oneButton;
      QPushButton *twoButton;
      QPushButton *threeButton;
      QPushButton *fourButton;
      QPushButton *fiveButton;
      QPushButton *sixButton;
      QPushButton *sevenButton;
      QPushButton *eightButton;
      QPushButton *nineButton;


      QPushButton *addButton;
      QPushButton *subButton;
      QPushButton *divButton;
      QPushButton *mulButton;
      QPushButton *equButton;
      QPushButton *timButton; //Time
      QPushButton *decButton;
      QPushButton *botButton;

      QPushButton *CEButton;
      QPushButton *ACButton;
      QPushButton *lefButton;
      QPushButton *rigButton;

private slots:

      void buttonZeroClicked();
      void buttonOneClicked();
      void buttonTwoClicked();
      void buttonThreeClicked();
      void buttonFourClicked();
      void buttonFiveClicked();
      void buttonSixClicked();
      void buttonSevenClicked();
      void buttonEightClicked();
      void buttonNineClicked();


      void buttonAddClicked();//+
      void buttonSubClicked();//-
      void buttonMulClicked();//乘
      void buttonDivClicked();//除
      void buttonTimClicked(); //时间
      void buttonDecClicked();//小数点
      void buttonBotClicked(); //加减号

      void buttonEquClicked();//等于号

      void buttonLefClicked();//左括号
      void buttonRigClicked();//右括号

      void buttonCEClicked();//CE
      void buttonACClicked();//AC
};

#endif // MAINWINDOW_H

 

 

 

 

 

 

calculator.cpp的代码

#include "calculator.h"
#include
using namespace std;
#include
#include
#include
#include
#pragma execution_character_set("utf-8")
bool isNum(char ch);
bool isOperate(char ch);
int level(char ch);
double scd(string s);
double getValue(vector V);
vector midToPost(string s);

calculator::calculator(QWidget *parent) : QMainWindow(parent)
{


       QWidget *widget=new QWidget; //构建一个QWidget布局将设置的布局添加进这个QWidget
       this->setCentralWidget(widget);

       inputLine=new QLineEdit;
       inputLine->setText(input);

       zeroButton=new QPushButton("0");
       oneButton=new QPushButton("1");
       twoButton=new QPushButton("2");
       threeButton=new QPushButton("3");
       fourButton=new QPushButton("4");
       fiveButton=new QPushButton("5");
       sixButton=new QPushButton("6");
       sevenButton=new QPushButton("7");
       eightButton=new QPushButton("8");
       nineButton=new QPushButton("9");
       decButton=new QPushButton(".");

       botButton=new QPushButton("±");
       timButton=new QPushButton("Time");
       addButton=new QPushButton("+");
       subButton=new QPushButton("-");
       mulButton=new QPushButton("*");
       divButton=new QPushButton("/");
       equButton=new QPushButton("=");

       lefButton=new QPushButton("(");
       rigButton=new QPushButton(")");
       CEButton=new QPushButton("CE");
       ACButton=new QPushButton("AC");

       QGridLayout *H=new QGridLayout(this); //声明了一个网格布局

       inputLine->setFixedHeight(50); //调整第一行大小
       CEButton->setFixedHeight(50);
       ACButton->setFixedHeight(50);

       H->addWidget(inputLine,0,0,1,3);
       H->setRowStretch(0,100);
       H->addWidget(CEButton,0,3);
       H->addWidget(ACButton,0,4);

       H->addWidget(oneButton,1,0);
       H->addWidget(twoButton,1,1);
       H->addWidget(threeButton,1,2);
       H->addWidget(botButton,1,3);
       H->addWidget(timButton,1,4);

       H->addWidget(fourButton,2,0);
       H->addWidget(fiveButton,2,1);
       H->addWidget(sixButton,2,2);
       H->addWidget(addButton,2,3);
       H->addWidget(subButton,2,4);

       H->addWidget(sevenButton,3,0);
       H->addWidget(eightButton,3,1);
       H->addWidget(nineButton,3,2);
       H->addWidget(mulButton,3,3);
       H->addWidget(divButton,3,4);

       H->addWidget(zeroButton,4,0);
       H->addWidget(decButton,4,1);
       H->addWidget(lefButton,4,2);
       H->addWidget(rigButton,4,3);
       H->addWidget(equButton,4,4);

       widget->setLayout(H); //将布局显示出来

       connect(zeroButton,SIGNAL(clicked()),this,SLOT(buttonZeroClicked()));//信号与槽函数
       connect(oneButton,SIGNAL(clicked()),this,SLOT(buttonOneClicked()));
       connect(twoButton,SIGNAL(clicked()),this,SLOT(buttonTwoClicked()));
      connect(threeButton,SIGNAL(clicked()),this,SLOT(buttonThreeClicked()));
       connect(fourButton,SIGNAL(clicked()),this,SLOT(buttonFourClicked()));
       connect(fiveButton,SIGNAL(clicked()),this,SLOT(buttonFiveClicked()));
       connect(sixButton,SIGNAL(clicked()),this,SLOT(buttonSixClicked()));
       connect(sevenButton,SIGNAL(clicked()),this,SLOT(buttonSevenClicked()));
       connect(eightButton,SIGNAL(clicked()),this,SLOT(buttonEightClicked()));
       connect(nineButton,SIGNAL(clicked()),this,SLOT(buttonNineClicked()));

       connect(addButton,SIGNAL(clicked()),this,SLOT(buttonAddClicked()));
       connect(subButton,SIGNAL(clicked()),this,SLOT(buttonSubClicked()));
       connect(mulButton,SIGNAL(clicked()),this,SLOT(buttonMulClicked()));
       connect(divButton,SIGNAL(clicked()),this,SLOT(buttonDivClicked()));

       connect(botButton,SIGNAL(clicked(bool)),this,SLOT(buttonBotClicked()));//正负号
       connect(timButton,SIGNAL(clicked(bool)),this,SLOT(buttonTimClicked()));//时间
       connect(decButton,SIGNAL(clicked(bool)),this,SLOT(buttonDecClicked()));//点号

       connect(lefButton,SIGNAL(clicked(bool)),this,SLOT(buttonLefClicked()));//左括号
       connect(rigButton,SIGNAL(clicked(bool)),this,SLOT(buttonRigClicked()));//右括号

       connect(CEButton,SIGNAL(clicked()),this,SLOT(buttonCEClicked()));
       connect(ACButton,SIGNAL(clicked()),this,SLOT(buttonACClicked()));

       connect(equButton,SIGNAL(clicked()),this,SLOT(buttonEquClicked())); //等于号*/

}

void calculator::buttonZeroClicked()  //以下是实现相应的槽函数
{
    if(input=="0")
    input='0';
    else input=input+'0';
    inputLine->setText(input);
}

void calculator::buttonOneClicked()
{
    if(input=="0")
    input='1';
    else input=input+'1';
    inputLine->setText(input);
}

void calculator::buttonTwoClicked()
{
    if(input=="0")
    input='2';
    else input=input+'2';
    inputLine->setText(input);
}

void calculator::buttonThreeClicked()
{
    if(input=="0")
    input='3';
    else input=input+'3';
    inputLine->setText(input);
}

void calculator::buttonFourClicked()
{
    if(input=="0")
    input='4';
    else input=input+'4';
    inputLine->setText(input);
}

void calculator::buttonFiveClicked()
{
    if(input=="0")
    input='5';
    else input=input+'5';
    inputLine->setText(input);
}

void calculator::buttonSixClicked()
{
    if(input=="0")
    input='6';
    else input=input+'6';
    inputLine->setText(input);
}

void calculator::buttonSevenClicked()
{
    if(input=="0")
    input='7';
    else input=input+'7';
    inputLine->setText(input);
}

void calculator::buttonEightClicked()
{
    if(input=="0")
    input='8';
    else input=input+'8';
    inputLine->setText(input);
}

void calculator::buttonNineClicked()
{
    if(input=="0")
    input='9';
    else input=input+'9';
    inputLine->setText(input);
}

void calculator::buttonAddClicked()
{
    if(input=="0")
    input='+';
    else input=input+'+';
    inputLine->setText(input);
}

void calculator::buttonSubClicked()
{
    if(input=="0")
    input='-';
    else input=input+'-';
    inputLine->setText(input);
}

void calculator::buttonMulClicked()
{
    if(input=="0")
    input='*';
    else input=input+'*';
    inputLine->setText(input);
}

void calculator::buttonDivClicked()
{
    if(input=="0")
    input='/';
    else input=input+'/';
    inputLine->setText(input);
}

void calculator::buttonTimClicked() //Time
{
   input=QDateTime::currentDateTime().toString("yyyy-MM-dd hh:mm:ss:zzz"); //格式化输出当前时间
   inputLine->setText(input);
}

void calculator::buttonDecClicked() //小数点
{
    if(input=="0")
    input='.';
    else input=input+'.';
    inputLine->setText(input);
}

void calculator::buttonBotClicked() //加减号
{
      if(input=="0")
        input='-';
      else
      {
      QString::iterator p=input.end();
        p--;
        if('-'==*p)
        input=input.left(input.length()-1);
        else input=input+'-';
     }
     inputLine->setText(input);
}

void calculator::buttonLefClicked()//左括号
{
    if(input=="0")
    input='(';
    else input=input+'(';
    inputLine->setText(input);
}

void calculator::buttonRigClicked()//右括号
{
    if(input=="0")
    input=')';
    else input=input+')';
    inputLine->setText(input);
}

void calculator::buttonCEClicked()
{
    input = input.left(input.length()-1); //减去一字符
    inputLine->setText(input);
}
void calculator::buttonACClicked() //直接清空
{
    input='0';
    inputLine->setText(input);
}

void calculator::buttonEquClicked()//等于号
{
  string inputTemp = input.toStdString();
  vector expression = midToPost(inputTemp);
  double value = getValue(expression);
  if(value != INT_MAX) {
    input=input+"="+QString::number(value);
    inputLine->setText(input);
  }else{
    input=input+"=syntax error";
    inputLine->setText(input);
  }
}

bool isNum(char ch) {
    if(ch >= '0' && ch <= '9') return true;
    else return false;
}

bool isOperate(char ch) {
    if(ch == '+' || ch == '-' || ch == '*' || ch == '/' || ch == '(' || ch == ')')
    return true;
    else return false;
}

int level(char ch) {
    switch(ch) {
        case '(' :
            return 5;
        case '*' :
            return 4;
        case '/' :
            return 4;
        case '+' :
            return 3;
        case '-' :
            return 3;
        case ')':
            return 2;
    }
}
/*字符串转数字*/
double scd(string s) {
    if(s.length() == 0) return INT_MAX;

    bool flag = false;
    for(int i = 0; i < s.length(); i++) {
        if(i == 0 && s[i] == '-') continue;
        else if(s[i] == '.' && !flag) {
            if(i > 0 && isNum(s[i-1])) {
                flag = true;
                continue;
            }
            else return INT_MAX;
        }
        else if(isNum(s[i])) continue;
        else return INT_MAX;
    }

    double result = atof(s.c_str());
    return result;
}

 /*由中缀表达式得到后缀表达式, 向量V存储结果*/
vector midToPost(string s) {
    stack S; /*符号栈*/
    vector V; /*后缀表达式*/
    int i = 0;
    while(i < s.length()) {
        if(isNum(s[i])) {
            string str = "";
            while(isNum(s[i]) || s[i] == '.') {
                str += s[i];
                i++;
            }
            V.push_back(str);
        }

        else if(isOperate(s[i])){
            /*负数情况*/
            if(s[i] == '-' && (i == 0 || !isNum(s[i-1])) {
                string str = "-"; i++;
                while(isNum(s[i]) || s[i] == '.') {
                    str += s[i]; i++;
                }
                V.push_back(str);
            }else{
                if(S.empty()){
                    S.push(s[i]); i++;
                }else {
                    int initial = level(s[i]);
                    if(initial == 2) {
                        while(level(S.top()) != 5 && !s.empty()) {
                            string str = "";
                            str += S.top();
                            V.push_back(str);
                            S.pop();
                        }
                        if(S.top() == '(') S.pop(); i++;
                    } else {
                        while(!S.empty() && initial <= level(S.top()) && level(S.top()) != 5) {
                            string str = "";
                            str += S.top();
                            V.push_back(str);
                            S.pop();
                        }
                        S.push(s[i]); i++;
                    }
                }
            }
        }
        else{
            cout << "表达式出错" << endl;
            V.clear();
            return V;
        }
    }
    while(!S.empty()) {
        string str = ""; str += S.top();
        S.pop();
        V.push_back(str);
    }
    //for(int i = 0; i < V.size(); i++) cout << V[i] << "[]";
    return V;
}

/*后缀表达式得到最终结果*/
double getValue(vector V) {
    stack S;
    for(int i = 0; i < V.size(); i++) {
    /*操作运算符*/
        if(V[i].length() == 1 && isOperate(V[i][0])) {
            double a = 0, b = 0;
            if(!S.empty()) {
                a = S.top(); S.pop();
            }else return INT_MAX;

            if(!S.empty()) {
                b = S.top(); S.pop();
            }else return INT_MAX;

            switch(V[i][0]) {
                case '+':
                    S.push(b+a);
                    break;
                case '-':
                    S.push(b-a);
                    break;
                case '*':
                    S.push(b*a);
                    break;
                case '/':
                    S.push(b/a);
                    break;
                default:
                    return INT_MAX;
            }
        }else {
            if(scd(V[i]) == INT_MAX) return INT_MAX;
            else S.push(scd(V[i]));
        }
    }
    if(S.empty()) return INT_MAX;

    double value = S.top();
    S.pop();
    return value;
}


calculator::~calculator()
{

}

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源码链接 https://download.csdn.net/download/zycxnanwang/11224121