QT实现简单计算器功能

本文实例为大家分享了QT实现简单计算器功能的具体代码，供大家参考，具体内容如下

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_OBJECT
protected:
? ? 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_H

mainwindow.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

来源：https://blog.csdn.net/kh971024/article/details/78306517