这篇文章主要讲解了“QT如何实现简单计算器功能”，文中的讲解内容简单清晰，易于学习与理解，下面请大家跟着小编的思路慢慢深入，一起来研究和学习“QT如何实现简单计算器功能”吧！
效果图：
新建工程，创建类MainWindow，基类是QMainWindow，声明变量和函数、槽
mainwindow.h
#ifndef MAINWINDOW_H#define MAINWINDOW_H #include <QMainWindow>#include <QPushButton>#include <QLineEdit> class MainWindow : public QMainWindow{ Q_OBJECTprotected: int num1,num2,result; //标记第一个数，第二个数和结果 int operat; //运算符号 int operat_flag;//标记是否输入符号 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_jia; QPushButton *button_jian; QPushButton *button_cheng; QPushButton *button_chu; QPushButton *button_result; QString s; public: MainWindow(QWidget *parent = 0); ~MainWindow(); public: void myLayout(); void operation(); void readNum(int num); void init_data();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_result_clicked(); void button_cheng_clicked(); void button_chu_clicked(); void button_jia_clicked(); void button_jian_clicked();}; #endif // MAINWINDOW_Hmainwindow.cpp
#include "mainwindow.h"#include <QPushButton>#include <QLineEdit>#include <QGridLayout> MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent){} void MainWindow::myLayout(){ QWidget *centerWindow = new QWidget; this->setCentralWidget(centerWindow); s = ""; init_data(); 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_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_jia->setMinimumHeight(50); button_jian->setMinimumHeight(50); button_cheng->setMinimumHeight(50); button_chu->setMinimumHeight(50); button_result->setMinimumHeight(50); //连接信号 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_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_ce,SIGNAL(clicked(bool)),this,SLOT(button_ce_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_1,2,1,Qt::Alignment()); layout->addWidget(button_2,2,2,Qt::Alignment()); layout->addWidget(button_3,2,3,Qt::Alignment()); layout->addWidget(button_jia,2,4,Qt::Alignment()); layout->addWidget(button_4,3,1,Qt::Alignment()); layout->addWidget(button_5,3,2,Qt::Alignment()); layout->addWidget(button_6,3,3,Qt::Alignment()); layout->addWidget(button_jian,3,4,Qt::Alignment()); layout->addWidget(button_7,4,1,Qt::Alignment()); layout->addWidget(button_8,4,2,Qt::Alignment()); layout->addWidget(button_9,4,3,Qt::Alignment()); layout->addWidget(button_cheng,4,4,Qt::Alignment()); layout->addWidget(button_ce,5,1,Qt::Alignment()); layout->addWidget(button_0,5,2,Qt::Alignment()); layout->addWidget(button_result,5,3,Qt::Alignment()); layout->addWidget(button_chu,5,4,Qt::Alignment()); layout->setMargin(12); centerWindow->setLayout(layout);} MainWindow::~MainWindow(){ } void MainWindow::init_data(){ num1 = 0; num2 = 0; operat_flag = 0;} void MainWindow::readNum(int num){ //如果是第一个操作数 if(operat_flag == 0){ num1 = num1 * 10 + num; } //如果是第二个操作数 else{ num2 = num2 * 10 + num; }} void MainWindow::operation(){ switch(operat){ case 1: result = num1 + num2; break; case 2: result = num1 - num2; break; case 3: result = num1 * num2; break; case 4: result = num1 / num2; break; } //把结果存到num1中，清零num2 num1 = result; num2 = 0; s = QString::number(result,10);} void MainWindow::button_0_clicked(){ s += "0"; data->setText(s); readNum(0);} void MainWindow::button_1_clicked(){ s += "1"; data->setText(s); readNum(1);} void MainWindow::button_2_clicked(){ s += "2"; data->setText(s); readNum(2);} void MainWindow::button_3_clicked(){ s += "3"; data->setText(s); readNum(3);} void MainWindow::button_4_clicked(){ s += "4"; data->setText(s); readNum(4);} void MainWindow::button_5_clicked(){ s += "5"; data->setText(s); readNum(5);} void MainWindow::button_6_clicked(){ s += "6"; data->setText(s); readNum(6);} void MainWindow::button_7_clicked(){ s += "7"; data->setText(s); readNum(7);} void MainWindow::button_8_clicked(){ s += "8"; data->setText(s); readNum(8);} void MainWindow::button_9_clicked(){ s += "9"; data->setText(s); readNum(9);} void MainWindow::button_ce_clicked(){ s = ""; data->setText(""); //初始化数据 init_data();} void MainWindow::button_jia_clicked(){ s += "+"; data->setText(s); operat_flag = 1; operat = 1;} void MainWindow::button_jian_clicked(){ s += "-"; data->setText(s); operat_flag = 1; operat = 2;} void MainWindow::button_cheng_clicked(){ s += "*"; data->setText(s); operat_flag = 1; operat = 3;} void MainWindow::button_chu_clicked(){ s += "/"; data->setText(s); operat_flag = 1; operat = 4;} void MainWindow::button_result_clicked(){ operation(); QString a = QString::number(result,10); 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(400,300); w.setWindowTitle("计算器"); w.myLayout(); return a.exec();}演示：
99*100=
结果
继续计算/99
感谢各位的阅读，以上就是“QT如何实现简单计算器功能”的内容了，经过本文的学习后，相信大家对QT如何实现简单计算器功能这一问题有了更深刻的体会，具体使用情况还需要大家实践验证。这里是编程网，小编将为大家推送更多相关知识点的文章，欢迎关注！
