C# get derived class propertiy-CodePudding

I've this base class that contains list of other classes

public class Blacklist
{
    public int Id { get; set; }

    public virtual IEnumerable<Card> Cards { get; set; }
}

Where Card class looks like

public class Card
{
    public int Id { get; set; }

    public string Cuid { get; set; }

    public int BlacklistId { get; set; }
}

Then I have implemented a derived class that extends Blacklist class

public class BlacklistTwo : Blacklist
{
    public new IEnumerable<CardTwo> Cards { get; set; }
}

where CardTwo class extends the base Card class

The problem occurs when I try to invoke a method that accept the base class as parameter with the derived instance. The type of outer class is alright but type of cards stays implemented as base class .

Example:

Insert(
   new BlacklistTwo(){
     Id = 1,
     Cards = new List<CardsTwo>()
     { new CardTwo() { Id = 123123, Cuid = "123213", BlacklistId = 1}});

public void Insert(Blacklist blacklist)
{
    blacklist.GetType(); // returns BlacklistTwo
    blacklist.Cards.GetType(); // returns IEnumerable<Card> insted of IEnumerable<CardTwo>
}

It works when I set the parameter of method to dynamic but I would like to avoid it if possible.

CodePudding user response：

As pointed out in comments - you don't actually override the property since you use the 'new' keyword. I think this may be what you are trying to achive:

public interface ICard
{
    int CardId { get; set; }
    string Cuid { get; set; }
    int BlacklistId { get; set; }
    //.. Other methods and properties
}
public class Card : ICard
{
    public int CardId { get; set; }
    public string Cuid { get; set; }
    public int BlacklistId { get; set; }
}

public class CardTwo : ICard
{
    public int CardId { get; set; }
    public string Cuid { get; set; }
    public int BlacklistId { get; set; }
}

public class Blacklist
{
    public int Id { get; set; }

    public virtual IEnumerable<ICard> Cards { get; set; }
}

public class BlacklistTwo : Blacklist
{
    public override IEnumerable<ICard> Cards { get; set; }

}

And then:

public Test()
{
    ICard card1 = new Card();
    card1.CardId = 123123;
    card1.Cuid = "123213";
    card1.BlacklistId = 1;

    ICard card2 = new CardTwo();
    card2.CardId = 123123;
    card2.Cuid = "123213";
    card2.BlacklistId = 1;

    Insert(new BlacklistTwo()
    {
        Id = 1,
        Cards = new List<ICard>() { card1 ,card2 }
    });

    if (card1 is Card c1)
    {
        //Yes - this is a type of Card
    }
    
    if (card2 is CardTwo c2)
    {
        //Yes - this is a type of CardTwo
    }
}

You could use an interface or an abstract class, and and probably even avoid extending the blacklist class