C＃中的属性编程

Question

I am new to Attribute programming. Not sure if i am asking the right question or not.

I have an abstract base class (AbstarctBase) and two drived classes Derived1 and Derived2. My AbstartBase class have two methods Method1 and Method2.

Is it possible to use attribute programming so that when I do this

AbstractBase ab= new Derived1();

I only get access to Method1 and when I use Derived2 class I only get access to Method2 .

Is this possible. If yes, then can you please give me an example to start with.

Answer 1

I think you are linking two different concepts of Inhetitance or Polymorphism and Attributes. In case of your problem what you can do is you can make an Inerface having a method and implement that differently in your deriving classes than use polymorphism to invoke that implementation that you require. For example

    public interface IBase
    {
      void Foo();
    }

    public class Derived1: IBase
    {
      public void Foo()
      {
        //Print Derived 1
      }
    }

    public class Derived2: IBase
    {
      public void Foo()
      {
        //Print Derived 2
      }
    }

   public class Program
   {
    public static void Main(String args[])
    {
      IBase base=new Derived1();
      base.Foo();//This prints Derived 1
      base=new Derived2();
      base.Foo();//This prints Derived 2
    }
   }

Where as Attributes in C# are used to attach metadata to your classes or class members, as well as when applying a common behaviour without having to implement a certain interface for each unit that shares the behaviour. They are used like this

    [MyAttribute]
    public class MyClass
    {
      //Class body
    }

You need to call the attribute by using GetCustomAttribute() method otherwise it will do nothing. For more information on attribute please refer this article http://www.codeproject.com/Articles/2933/Attributes-in-C Hope this hepls you.