Visual C++ .NET/Class/attribute

Creating Custom attribute

 
#include "stdafx.h"
using namespace System;
[AttributeUsageAttribute(AttributeTargets::Assembly | AttributeTargets::Class)]
public ref class OwnerAttribute : Attribute
{
   public:
      property String^ DevOwner;
      property String^ TestOwner;
      OwnerAttribute() { }
};
[ Owner(DevOwner="John") ]
ref class C2
{
};

int main()
{
    Attribute^ attribute = Attribute::GetCustomAttribute( C2::typeid,OwnerAttribute::typeid);
    if (attribute != nullptr)
    {
         Console::WriteLine("{0}", attribute);
    }
}

Custom attribute

 
#include "stdafx.h"
using namespace System;
[AttributeUsageAttribute(AttributeTargets::All)]
public ref class OwnerAttribute : Attribute{
   public:
      property String^ DevOwner;
      property DateTime^ CreationDate;
      OwnerAttribute(){ }
      OwnerAttribute(String^ _DevOwner)
      {
         DevOwner = _DevOwner;
      }
};
[ Owner("Smith")]
ref class C1
{
};
[ Owner(DevOwner="Smith") ]
ref class C2
{
};

Obsolete attribute

 
#include "stdafx.h"
using namespace System;
ref class C
{
   public:
     void Method2() {}
    [Obsolete("This method is obsolete; use Method2 instead.")]
     void Method1() {}
};
int main()
{
    C^ c = gcnew C();
    c->Method1();
    c->Method2();
}

Out attribute parameter

 
// compile with: /clr:safe or /clr:pure
#include "stdafx.h"
using namespace System;
using namespace System::Runtime::InteropServices;
public ref class C1
{
       public:
       void Func([Out] String^% text)
       {
           text = "testing";
       }
}

Use the FlagsAttribute

 
#include "stdafx.h"
using namespace System;

[ Flags ]
enum class Color
{
    Red = 1,
    Blue = 2,
    Green = 4   // use powers of 2
};
int main()
{
   Console::WriteLine("Colors: {0}, {1}, {2}", Color::Red, Color::Blue,Color::Green);
   Console::WriteLine("Colors: {0:d}, {1:d}, {2:d}", Color::Red, Color::Blue,Color::Green);
   Color c = Color::Red | Color::Blue;
   String^ s1 = c.ToString("X"); 
   Console::WriteLine( s1 );

   String^ s2 = Enum::Format( Color::typeid, c , "G");
   Console::WriteLine(s2 );
}