Error in Generic Classes

Question

Hello, 

I have a problem while using generic class. I would like to describe it with code;

    public interface IBaseValidator<T> where T : BaseEntity
    {

        void CreateValidator(T entity);
        void UpdateValidator(T entity);
        void DeleteValidator(T entity);

    }

    class UserValidator : IBaseValidator<User>
    {
        public void CreateValidator(User entity)
        {
            //TODO
        }

        public void UpdateValidator(User entity)
        {
            //TODO
        }

        public void DeleteValidator(User entity)
        {
            //TODO
        }
    }


    public class UserManager<T> where T : BaseEntity
    {
        private IBaseValidator<T> _validator;
        
public UserManager()
        {
            _validator = new UserValidator();
        }
}

for this line it gives this error : Cannot implicity convert type 'UserValidator' to 'IBaseValidator<T>'. An explicit conversion exists (are you missing a cast?)

_validator = new UserValidator();

Answer 1

Change the UserManager class to the following:

public class UserManager<T> where T : BaseEntity
{
    private IBaseValidator<T> _validator;

    public UserManager(IBaseValidator<T> validator)
    {
        _validator = validator;
    }
}

Then use the constructor of UserManager to initiate a new instance of UserValidator().
This is called dependency injection.

Answer 2

Thank you so much