Using generic method with an interface as a constraint type
suggest changeThis is an example of how to use the generic type TFood inside Eat method on the class Animal
public interface IFood
{
void EatenBy(Animal animal);
}
public class Grass: IFood
{
public void EatenBy(Animal animal)
{
Console.WriteLine("Grass was eaten by: {0}", animal.Name);
}
}
public class Animal
{
public string Name { get; set; }
public void Eat<TFood>(TFood food)
where TFood : IFood
{
food.EatenBy(this);
}
}
public class Carnivore : Animal
{
public Carnivore()
{
Name = "Carnivore";
}
}
public class Herbivore : Animal, IFood
{
public Herbivore()
{
Name = "Herbivore";
}
public void EatenBy(Animal animal)
{
Console.WriteLine("Herbivore was eaten by: {0}", animal.Name);
}
}
You can call the Eat method like this:
var grass = new Grass();
var sheep = new Herbivore();
var lion = new Carnivore();
sheep.Eat(grass);
//Output: Grass was eaten by: Herbivore
lion.Eat(sheep);
//Output: Herbivore was eaten by: Carnivore
In this case if you try to call:
sheep.Eat(lion);
It won’t be possible because the object lion does not implement the interface IFood. Attempting to make the above call will generate a compiler error: “The type ‘Carnivore’ cannot be used as type parameter ‘TFood’ in the generic type or method ‘Animal.Eat(TFood)’. There is no implicit reference conversion from ‘Carnivore’ to ‘IFood’.”
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