3.QT计算机实战

• mainwindow.h

  #ifndef MAINWINDOW_H
  #define MAINWINDOW_H
  
  #include <QMainWindow>
  
  namespace Ui {
  class MainWindow;
  }
  
  class MainWindow : public QMainWindow
  {
      Q_OBJECT
  
  public:
      explicit MainWindow(QWidget *parent = 0);
      void run();
      ~MainWindow();
  
  private slots:
      void on_pushButton_clicked();
  
      void on_num1_textChanged(const QString &arg1);
  
  private:
      Ui::MainWindow *ui;
  };
  
  #endif // MAINWINDOW_H

• mainwindow.cpp

  #include "mainwindow.h"
  #include "ui_mainwindow.h"
  #include "op.h"
  #include <QDebug>
  
  MainWindow::MainWindow(QWidget *parent) :
      QMainWindow(parent),
      ui(new Ui::MainWindow)
  {
      ui->setupUi(this);
  }
  
  MainWindow::~MainWindow()
  {
      delete ui;
  }
  
  const QString op1("+");
  const QString op2("-");
  const QString op3("*");
  const QString op4("/");
  
  void MainWindow::on_pushButton_clicked()
  {
      qDebug()<<"hello"<<endl;
      op ops;
      bool isok;
      QString str1 = ui->num1->text();
      QString str2 = ui->op->text();
      QString str3 = ui->num2->text();
      //保存结果
      QString str4;
      int a = str1.toInt(&isok,10);
      int b = str3.toInt(&isok,10);
  
      ops.seta(a);
      ops.setb(b);
  
      if(str2 == op1)
      {
          str4.sprintf("%d",ops.add());
          qDebug()<<str4<<endl;
      }
      else if(str2 == op2)
      {
          str4.sprintf("%d",ops.sub());
          qDebug()<<str4<<endl;
      }
      else if(str2 == op3)
      {
          str4.sprintf("%d",ops.mul());
           qDebug()<<str4<<endl;
      }
      else if(str2 == op4)
      {
          str4.sprintf("%d",ops.divv());
           qDebug()<<str4<<endl;
      }
      ui->textEdit->setText(str4);
  }
  
  void MainWindow::run()
  {
      qDebug()<<"hello"<<endl;
      op ops;
      bool isok;
      QString str1 = ui->num1->text();
      QString str2 = ui->op->text();
      QString str3 = ui->num2->text();
      //保存结果
      QString str4;
      int a = str1.toInt(&isok,10);
      int b = str3.toInt(&isok,10);
  
      ops.seta(a);
      ops.setb(b);
  
      if(str2 == op1)
      {
          str4.sprintf("%d",ops.add());
          qDebug()<<str4<<endl;
      }
      else if(str2 == op2)
      {
          str4.sprintf("%d",ops.sub());
          qDebug()<<str4<<endl;
      }
      else if(str2 == op3)
      {
          str4.sprintf("%d",ops.mul());
           qDebug()<<str4<<endl;
      }
      else if(str2 == op4)
      {
          str4.sprintf("%d",ops.divv());
           qDebug()<<str4<<endl;
      }
      ui->textEdit->setText(str4);
  }
  
  
  void MainWindow::on_num1_textChanged(const QString &arg1)
  {
      qDebug()<<"hello"<<endl;
      op ops;
      //父类存储子类对象的地址
      QObject *pobj = &ops;
  
      bool isok;
      QString str1 = ui->num1->text();
      int a = str1.toInt(&isok,10);
      if(!isok)
      {
          ui->num1->clear();
      }
  }

• op.h

  #ifndef OP_H
  #define OP_H
  
  #include <QObject>
  
  class op : public QObject
  {
      Q_OBJECT
  public:
      explicit op(QObject *parent = nullptr);
      int add();
      int sub();
      int mul();
      int divv();
  
  public:
      void seta(int data);
      void setb(int data);
      int geta();
      int getb();
  
  private:
      int a;
      int b;
  
  
  signals:
  
  public slots:
  };
  
  #endif // OP_H

• op.cpp

  #include "op.h"
  
  op::op(QObject *parent) : QObject(parent)
  {
      a = b = 0;
  }
  
  int op::add()
  {
      return a+b;
  }
  
  int op::sub()
  {
      return a-b;
  }
  
  int op::mul()
  {
      return a*b;
  }
  
  int op::divv()
  {
      return a/b;
  }
  
  void op::seta(int data)
  {
      a = data;
  }
  
  void op::setb(int data)
  {
      b = data;
  }
  
  int op::geta()
  {
      return a;
  }
  
  int op::getb()
  {
      return b;
  }

• main.cpp

  #include "mainwindow.h"
  #include <QApplication>
  
  int main(int argc, char *argv[])
  {
      QApplication a(argc, argv);
      MainWindow w;
      w.show();
  
      return a.exec();
  }