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 = );
      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,);
       int b = str3.toInt(&isok,);
  
       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,);
       int b = str3.toInt(&isok,);
  
       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,);
       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 = ;
   }
  
   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();
   }