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

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持源码搜藏网。