Question

I want to access to static fields of a type, which is a class, introduced in a generic function. But compiler always gives me this error

‘T’ is a ‘type parameter’, which is
not valid in the given context

here is the code.

 public class A
  {
    public static int Num = 1;
    public int GetClassNum<T>() where T : A
    {
      //return T.Num;
      //return default(T).Num;
      //return what???
    }
  }

  public class B : A
  {
    public static int Num = 2;
  }

  public class C : A
  {
    public static int Num = 3;
  }

I suspect that this has something to do with the fact that interfaces are generally used to filter the typename in a generic function. or must it be always? In this case there should not be a static field. Is there any way I can achieve?

Answer 1

try this:

public class A
  {
    private static int _num = 1;
    public  virtual int Num { get { return _num; } set { _num = value; } }
    public int GetClassNum<T>(T input) where T : A
    {
      return input.Num;
    }
  }

Then override Num in the derived classes