Qt實踐——簡易計算器
阿新 • • 發佈：2018-12-10
這個計算器實現了帶括號的加減乘除浮點數運算，但由於時間問題，我沒有新增浮點數的大數類，只是實現了一個簡易計算器。下面上程式：
mainwindow.h
#ifndef MAINWINDOW_H #define MAINWINDOW_H #include <QMainWindow> #include <QPushButton> #include <QLineEdit> class MainWindow : public QMainWindow { Q_OBJECT protected: double result; QLineEdit *data; QPushButton *button_0; QPushButton *button_1; QPushButton *button_2; QPushButton *button_3; QPushButton *button_4; QPushButton *button_5; QPushButton *button_6; QPushButton *button_7; QPushButton *button_8; QPushButton *button_9; QPushButton *button_ce; QPushButton *button_point; QPushButton *button_lbracket; QPushButton *button_rbracket; QPushButton *button_delete; QPushButton *button_jia; QPushButton *button_jian; QPushButton *button_cheng; QPushButton *button_chu; QPushButton *button_result; QString s; public: MainWindow(QWidget *parent = 0); ~MainWindow(); public: void layout(); void operation(); void init(); private slots: void button_0_clicked(); void button_1_clicked(); void button_2_clicked(); void button_3_clicked(); void button_4_clicked(); void button_5_clicked(); void button_6_clicked(); void button_7_clicked(); void button_8_clicked(); void button_9_clicked(); void button_ce_clicked(); void button_point_clicked(); void button_lbracket_clicked(); void button_rbracket_clicked(); void button_delete_clicked(); void button_result_clicked(); void button_cheng_clicked(); void button_chu_clicked(); void button_jia_clicked(); void button_jian_clicked(); }; #endif // MAINWINDOW_H
mainwindow.cpp
#include "mainwindow.h" #include <QPushButton> #include <QLineEdit> #include <QGridLayout> #include <stack> #include <iostream> using namespace std; char infix[1000],suffix[1000]; int k=0; MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent) { } void MainWindow::layout() { QWidget *centerWindow = new QWidget; this->setCentralWidget(centerWindow); s = ""; init(); data = new QLineEdit(""); button_0 = new QPushButton("0"); button_1 = new QPushButton("1"); button_2 = new QPushButton("2"); button_3 = new QPushButton("3"); button_4 = new QPushButton("4"); button_5 = new QPushButton("5"); button_6 = new QPushButton("6"); button_7 = new QPushButton("7"); button_8 = new QPushButton("8"); button_9 = new QPushButton("9"); button_ce = new QPushButton("CE"); button_point = new QPushButton("."); button_lbracket = new QPushButton("("); button_rbracket = new QPushButton(")"); button_delete = new QPushButton("<-"); button_jia = new QPushButton("+"); button_jian = new QPushButton("-"); button_cheng = new QPushButton("*"); button_chu = new QPushButton("/"); button_result = new QPushButton("="); data->setFixedHeight(30); button_0->setMinimumHeight(50); button_1->setMinimumHeight(50); button_2->setMinimumHeight(50); button_3->setMinimumHeight(50); button_4->setMinimumHeight(50); button_5->setMinimumHeight(50); button_6->setMinimumHeight(50); button_7->setMinimumHeight(50); button_8->setMinimumHeight(50); button_9->setMinimumHeight(50); button_ce->setMinimumHeight(50); button_point->setMinimumHeight(50); button_lbracket->setMinimumHeight(50); button_rbracket->setMinimumHeight(50); button_delete->setMinimumHeight(50); button_jia->setMinimumHeight(50); button_jian->setMinimumHeight(50); button_cheng->setMinimumHeight(50); button_chu->setMinimumHeight(50); button_result->setMinimumHeight(50); //連線訊號 connect(button_0,SIGNAL(clicked(bool)),this,SLOT(button_0_clicked())); connect(button_1,SIGNAL(clicked(bool)),this,SLOT(button_1_clicked())); connect(button_2,SIGNAL(clicked(bool)),this,SLOT(button_2_clicked())); connect(button_3,SIGNAL(clicked(bool)),this,SLOT(button_3_clicked())); connect(button_4,SIGNAL(clicked(bool)),this,SLOT(button_4_clicked())); connect(button_5,SIGNAL(clicked(bool)),this,SLOT(button_5_clicked())); connect(button_6,SIGNAL(clicked(bool)),this,SLOT(button_6_clicked())); connect(button_7,SIGNAL(clicked(bool)),this,SLOT(button_7_clicked())); connect(button_8,SIGNAL(clicked(bool)),this,SLOT(button_8_clicked())); connect(button_9,SIGNAL(clicked(bool)),this,SLOT(button_9_clicked())); connect(button_ce,SIGNAL(clicked(bool)),this,SLOT(button_ce_clicked())); connect(button_point,SIGNAL(clicked(bool)),this,SLOT(button_point_clicked())); connect(button_lbracket,SIGNAL(clicked(bool)),this,SLOT(button_lbracket_clicked())); connect(button_rbracket,SIGNAL(clicked(bool)),this,SLOT(button_rbracket_clicked())); connect(button_delete,SIGNAL(clicked(bool)),this,SLOT(button_delete_clicked())); connect(button_jia,SIGNAL(clicked(bool)),this,SLOT(button_jia_clicked())); connect(button_jian,SIGNAL(clicked(bool)),this,SLOT(button_jian_clicked())); connect(button_cheng,SIGNAL(clicked(bool)),this,SLOT(button_cheng_clicked())); connect(button_chu,SIGNAL(clicked(bool)),this,SLOT(button_chu_clicked())); connect(button_result,SIGNAL(clicked(bool)),this,SLOT(button_result_clicked())); QGridLayout * layout = new QGridLayout; layout->addWidget(data,1,1,1,4,Qt::Alignment()); layout->addWidget(button_ce,2,1,Qt::Alignment()); layout->addWidget(button_delete,2,2,Qt::Alignment()); layout->addWidget(button_lbracket,2,3,Qt::Alignment()); layout->addWidget(button_rbracket,2,4,Qt::Alignment()); layout->addWidget(button_1,3,1,Qt::Alignment()); layout->addWidget(button_2,3,2,Qt::Alignment()); layout->addWidget(button_3,3,3,Qt::Alignment()); layout->addWidget(button_jia,3,4,Qt::Alignment()); layout->addWidget(button_4,4,1,Qt::Alignment()); layout->addWidget(button_5,4,2,Qt::Alignment()); layout->addWidget(button_6,4,3,Qt::Alignment()); layout->addWidget(button_jian,4,4,Qt::Alignment()); layout->addWidget(button_7,5,1,Qt::Alignment()); layout->addWidget(button_8,5,2,Qt::Alignment()); layout->addWidget(button_9,5,3,Qt::Alignment()); layout->addWidget(button_cheng,5,4,Qt::Alignment()); layout->addWidget(button_result,6,1,Qt::Alignment()); layout->addWidget(button_0,6,2,Qt::Alignment()); layout->addWidget(button_point,6,3,Qt::Alignment()); layout->addWidget(button_chu,6,4,Qt::Alignment()); layout->setMargin(12); centerWindow->setLayout(layout); } MainWindow::~MainWindow() { } void MainWindow::init() { s = ""; } //符號優先順序判斷 int mycmp(char a, char b) { if(b == '(') return 1;//左括號直接入棧 else if((b == '*' || b == '/') &&(a == '+' || a == '-' || a == '(')) return 1;//*、/優先順序高於+、-、(，入棧 else if((b == '+' || b == '-') && (a == '(')) return 1;//+、-優先順序高於(，入棧 else return 0; } //中綴表示式轉字尾表示式 void infix_to_suffix(char* infix, char* suffix) { int i, j=0, top=0; char stack[1000];//儲存運算子的棧 for(i=0; infix[i]!='\0'; i++) { if((infix[i] >= '0' && infix[i] <= '9')||infix[i] == '.' ) { suffix[j++] = infix[i];//運算元則直接輸出 } else { if(i != 0 && ((infix[i-1] >= '0' && infix[i-1] <= '9')||infix[i] == '.') ) { suffix[j++] = ' ';//運算元後補充空格分割 } if(infix[i] == ')') { //遇到右括號則一直彈出直到左括號，但左括號不輸出 while(stack[top-1] != '(') { suffix[j++] = stack[--top]; suffix[j++] = ' '; } top--; } else if(top == 0 || mycmp(stack[top-1], infix[i])) { //棧為空或當前操作符的優先順序高於棧頂操作符，當前操作符入棧 stack[top++] = infix[i]; } else { //當前操作符優先順序等於或低於棧頂操作符則彈出棧頂 while(!mycmp(stack[top-1], infix[i])) { suffix[j++] = stack[--top]; suffix[j++] = ' '; if(top == 0) break; } stack[top++] = infix[i];//當前操作符入棧 } } } //補充空格分割 if(suffix[j-1] != ' ') { suffix[j++] = ' '; } //如果操作符棧不為空，彈出所有操作符 while(top != 0) { suffix[j++] = stack[--top]; suffix[j++] = ' '; } suffix[j] = '\0'; } //字尾表示式求值 double suffix_value(char* suffix) { int i; double stack[1000]; int top = 0; double value = 0.0; double temp = 0.0; double exp = 0.1; for(i=0; suffix[i] != '\0'; i++) { if(suffix[i] >= '0' && suffix[i] <= '9') { while(suffix[i] >= '0' && suffix[i] <= '9') { value = value*10 + suffix[i] - '0'; i++; } i--; } else if(suffix[i] == '.') { i++; while(suffix[i] >= '0' && suffix[i] <= '9') { temp = temp + (suffix[i] - '0') * exp; i++; exp = exp * 0.1; } i--; value = value + temp; } else if(suffix[i] == ' ') { //運算元入棧 stack[top++] = value; value = 0; temp = 0; exp = 0.1; } else { //根據操作符，對棧頂兩個運算元進行計算並得到結果 switch(suffix[i]) { case '+': value = stack[top-2] + stack[top-1];break; case '-': value = stack[top-2] - stack[top-1];break; case '*': value = stack[top-2] * stack[top-1];break; case '/': value = stack[top-2] / stack[top-1];break; default: break; } top -= 2; } } return stack[0]; } void MainWindow::operation() { infix_to_suffix(infix, suffix); result = suffix_value(suffix); s = QString::number(result,10.0); } void getnum(char num) { infix[k++]=num; } void MainWindow::button_0_clicked() { s += "0"; data->setText(s); getnum('0'); } void MainWindow::button_1_clicked() { s += "1"; data->setText(s); getnum('1'); } void MainWindow::button_2_clicked() { s += "2"; data->setText(s); getnum('2'); } void MainWindow::button_3_clicked() { s += "3"; data->setText(s); getnum('3'); } void MainWindow::button_4_clicked() { s += "4"; data->setText(s); getnum('4'); } void MainWindow::button_5_clicked() { s += "5"; data->setText(s); getnum('5'); } void MainWindow::button_6_clicked() { s += "6"; data->setText(s); getnum('6'); } void MainWindow::button_7_clicked() { s += "7"; data->setText(s); getnum('7'); } void MainWindow::button_8_clicked() { s += "8"; data->setText(s); getnum('8'); } void MainWindow::button_9_clicked() { s += "9"; data->setText(s); getnum('9'); } void MainWindow::button_ce_clicked() { s = ""; data->setText(""); //初始化資料 init(); memset(infix,0,1000); memset(suffix,0,1000); k = 0; } void MainWindow::button_point_clicked() { s += "."; data->setText(s); getnum('.'); } void MainWindow::button_lbracket_clicked() { s += "("; data->setText(s); getnum('('); } void MainWindow::button_rbracket_clicked() { s += ")"; data->setText(s); getnum(')'); } void MainWindow::button_delete_clicked() { s=s.left(s.length()-1); data->setText(s); k--; } void MainWindow::button_jia_clicked() { s += "+"; data->setText(s); getnum('+'); } void MainWindow::button_jian_clicked() { s += "-"; data->setText(s); getnum('-'); } void MainWindow::button_cheng_clicked() { s += "*"; data->setText(s); getnum('*'); } void MainWindow::button_chu_clicked() { s += "/"; data->setText(s); getnum('/'); } void MainWindow::button_result_clicked() { infix[k]='\0'; operation(); QString a = QString::number(result,10.0); data->setText(a); }
main.cpp
#include "mainwindow.h"
#include <QApplication>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MainWindow w;
w.show();
w.setFixedSize(500,500);
w.setWindowTitle("計算器");
w.layout();
return a.exec();
}最終實現結果為：
