c# generics error: The constraints for type parameter 'T' of method …?

Question

Getting the following error:

Error 1 The constraints for type parameter \'T\' of method
\'genericstuff.Models.MyClass.GetC

Answer 1

You either need to apply the constraint to the interface method as well or remove it from the implementation.

You are changing the interface contract by changing the constraint on the implementation - this isn't allowed.

public interface IMyClass
{
    int GetCount(string filter) where T : class;
}