CODEWITHSUNDEEP
c#.netgenericstypes
anon
anon

Reputation:

Overriding base class type with derived type

I have a baseclass called RottenFruit, a class called RottenApple that inherints from it.

Now i want the RottenFruit class to inherit a class called Fruit, which is a base class for the Apple class, so I can add a Fruit object under each RottenFruit object, making it generic in terms of the types of fruit. 

abstract class RottenFruits : Fruit
{
    public virtual Fruit fruit { get; set; }; 
    bool isRotten { get; set; }
}

class RottenApple : RottenFruits
{
    public override Apple fruit { get; set; };
}

If i Try this I get an error in the derived class saying

Type must be Fruit to match overridden member RottenFruits.fruit Why dosen't the type match when Fruit is a baseclass of Apple?

Edit: Lets say I have multiple RottenFruits: RottenBanana, RottenPear, etc. and I want to gather them all in an array. RottenFruits will expect a type parameter of Fruit if I use a generic type

RottenFruits[] fruits = new { 
    new RottenApple(){fruit = new Apple()}, 
    new RottenBanana(){fruit = new Banana() 
}

Upvotes: 0

Views: 250

Answers (1)

Ehsan Sajjad
Ehsan Sajjad

Reputation: 62488

You cannot do the way you are trying it. i think what you can do is use generics here:

class Fruit
{
}
class abstract RottenFruits<T> : Fruit where T : class
{
    public T fruit; 
    bool isRotten { get; set; }
}

and now you can do it:

class RottenApple : RottenFruits<Apple>
{

}

Upvotes: 4

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