Visual C++ .NET/Class/virtual method

Материал из .Net Framework эксперт
Версия от 12:05, 26 мая 2010; Admin (обсуждение | вклад) (1 версия)
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Explicit override

 
#include "stdafx.h"
using namespace System;
ref class MyClass{
   public:
      void Initialize(bool fromFile)
      {
         if (fromFile)
         {
             Read();
         }
      }
      virtual void Read()
      {
         Console::WriteLine("MyClass::Read");
      }
};
ref class MySubClass : MyClass
{
};
ref class MySubSubClass : MySubClass{
   public:
      virtual void MyClassRead() = MyClass::Read
      {
          Console::WriteLine("MySubSubClass::MyClassRead");
      }
      virtual void Read() new
      {
          Console::WriteLine("MySubSubClass::Read");
      }
};
int main()
{
   MySubSubClass^ scroll = gcnew MySubSubClass();
   MySubClass^ item = scroll;
   item->Initialize(true);
   scroll->Read();
}


Native managed virtual

 
#include "stdafx.h"
class MyBaseClass
{
   public:
   MyBaseClass()
   {
      myvirtual();
   }
   virtual void myvirtual()
   {
      System::Console::WriteLine("MyBaseClass::myvirtual");
   }
};
class NativeDerived : public MyBaseClass
{
   public:
   NativeDerived()
   {
      myvirtual();
   }
   virtual void myvirtual()
   {
      System::Console::WriteLine("NativeDerived::myvirtual");
   }
};
ref class ManagedBase
{
   public:
   ManagedBase()
   {
      myvirtual();
   }
   virtual void myvirtual()
   {
      System::Console::WriteLine("ManagedBase::myvirtual");
   }
};
ref class ManagedDerived : ManagedBase
{
   public:
   ManagedDerived()
   {
      myvirtual();
   }
   virtual void myvirtual() override
   {
      System::Console::WriteLine("ManagedDerived::myvirtual");
   }
};
int main()
{
   NativeDerived nd;
   ManagedDerived rd;
}


new method

 
#include "stdafx.h"
using namespace System;
ref class MyClass
{
   public:
      void Initialize(bool fromFile)
      {
         if (fromFile)
         {
             Read();
         }
      }
      virtual void Read()
      {
         Console::WriteLine("MyClass::Read");
      }
};
ref class MySubClass : MyClass
{
};
ref class MySubSubClass : MySubClass
{
   public:
      virtual void Read() new
      {
          Console::WriteLine("MySubSubClass::Read");
      }
};
int main()
{
   MySubSubClass^ scroll = gcnew MySubSubClass();
   MySubClass^ item = scroll;
   item->Initialize(true);
   scroll->Read();
}


override and virtual method

 
#include "stdafx.h"
using namespace System;
ref class MyClass{
   public:
      void Initialize(bool fromFile)
      {
         if (fromFile)
         {
             Read();
         }
      }
      virtual void Read()
      {
         Console::WriteLine("MyClass::Read");
      }
};
ref class MySubClass : MyClass
{
};
ref class MySubSubClass : MySubClass
{
   public:
      virtual void Read() override
      {
          Console::WriteLine("MySubSubClass::Read");
      }
};
int main()
{
   MySubSubClass^ scroll = gcnew MySubSubClass();
   MySubClass^ item = scroll;
   item->Initialize(true);
   scroll->Read();
}


Virtual methods

 
#include "stdafx.h"
using namespace System;
ref class Animal{
public:
    virtual void Speak (){
        Console::WriteLine("Animal");
    }
};
ref class Dog : public Animal{
public:
    virtual void Speak() override{
        Console::WriteLine("Dog");
    }
};
ref class Puppy : public Dog{
public:
    virtual void Yip() = Dog::Speak
    {
        Console::WriteLine("Puppy");
    }
};
ref class Cat : public Animal{
public:
    virtual void Speak() new
    {
        Console::WriteLine("Cat");
    }
};
ref class Tiger : public Cat{
public:
  virtual void Growl() = Animal::Speak, Cat::Speak
    {
        Console::WriteLine("Tiger");
    }
};
void main()
{
    array<Animal^>^ animals = gcnew array<Animal^> { 
        gcnew Animal(), 
        gcnew Dog(), 
        gcnew Puppy(),
        gcnew Cat(), 
        gcnew Tiger() 
   };
    for each ( Animal ^a in animals){
        a->Speak();
    }
    Console::WriteLine();
    Animal^ cat1 = gcnew Cat();
    Cat^  cat2   = gcnew Cat();
    Cat^  tiger  = gcnew Tiger();
    cat1->Speak();
    cat2->Speak();
    tiger->Speak();
}