Need help filling a list with all classes that inherit from an interface

Hi everyone! Now Im sorry for this kind of question, I feel kind of stupid for asking this lol but on to the problem:

So in my game there are enemies which they all can have random special abilities. I want to be able to change/switch out these abilities easily in the future by just creating/deleting one of the ability classes. These ability classes all inherit from the IPassiveAbility interface which does NOT inherit from monobehaviour.

I thought it would be a good idea to make a class called PassiveAbilitiesList where at the beginning of the game I just let it go through all classes inheriting from IPassiveAbility, put them into a list and whenever an enemy comes up he gets a random ability from the list but I cant figure out how I can put objects of these classes into the list without hardcoding every ability into the list myself. So basically what Im asking for would be this:

Code (CSharp):

1. public class PassiveAbilitiesList : MonoBehaviour
2. {
3.     private List<IPassiveAbility> abilitiesList = new List<IPassiveAbility>();
4.  
5.     void Start()
6.     {
7.         foreach(IPassiveAbility pa in Assets/scripts)
8.         {
9.             abilitiesList.Add(new pa);
10.         }
11.     }
12. }

Is this, or something similair to this where it will get all passive abilities and put it into a list on its own, somehow possible? Can I go through the folder and get all classes which inherit IPassiveAbility and just make a new object of them or something similair to that? If not, would you suggest writing this instead or do you have better suggestions?

Code (CSharp):

1. public class PassiveAbilitiesList : MonoBehaviour
2. {
3.     private List<IPassiveAbility> abilitiesList = new List<IPassiveAbility>();
4.  
5.     void Start()
6.     {
7.         abilitiesList.Add(new Ability1);
8.         abilitiesList.Add(new Ability2);
9.         abilitiesList.Add(new Ability3);
10.         abilitiesList.Add(new Ability4);
11.         etc.
12.     }
13. }

Thanks for your time and answers in advance already. I know this is kind of a retarded question but im seriously lost on how that would be possible to do since having to hardcode every ability would be a pain in the long run

Edit: Just for reference even if its pretty empty but this is my IPassiveAbility interface:

Code (CSharp):

1. public class IPassiveAbility
2. {
3.     private string name;
4.     private string description;
5.  
6.     public string GetName()
7.     {
8.         return name;
9.     }
10.  
11.     public string GetDescription()
12.     {
13.         return description;
14.     }
15. }

Edit 2: Just realised that my interface is not an interface my bad... Sorry Im pretty new to coding and Im not really sure but I think what I really want is an abstract class and not an interface. Please correct me if Im wrong.

 

You can do this pretty simply with reflection. Here's a good method: https://stackoverflow.com/questions...embly-that-inherit-from-a-specific-type-c-sha

Use "typeof(IPassiveAbility)" as the base type parameter and "Assembly.GetExecutingAssembly()" as the assembly parameter.

 

Cant get it to work. It tells me that I cant implicitly cast an IEnumerable<Type> to an List<IPassiveAbility> or just an IPassiveAbility and that an explicit cast exists and I might want to use that which makes sense but I cant figure out how I could cast it. Just to make sure, this is what I wrote:

Code (CSharp):

1. public IEnumerable<Type> FindDerivedTypes(Assembly assembly, Type baseType)
2.     {
3.         return assembly.GetTypes().Where(t => t != baseType && baseType.IsAssignableFrom(t));
4.     }

and this is how I call it:

Code (CSharp):

1.  
2.         // Try 1
3.         abilitiesList = FindDerivedTypes(Assembly.GetExecutingAssembly(), typeof(IPassiveAbility));
4.  
5.         // Try 2
6.         abilitiesList.Add(FindDerivedTypes(Assembly.GetExecutingAssembly(), typeof(IPassiveAbility)));
7.  
8.         // Try 3  
9.         foreach(Type t in FindDerivedTypes(Assembly.GetExecutingAssembly(), typeof(IPassiveAbility)))
10.         {
11.             abilitiesList.Add(t);
12.         }
13.  

 

Well yeah, the method i gave you returns a bunch of types. You need to then get an instance of each type if you want to add them to a List<IPassiveAbility>. This is a pretty good way to do that: https://docs.microsoft.com/en-us/do...edirectedfrom=MSDN&view=netcore-3.1#overloads

Code (CSharp):

1. var abilitiesList = new List<IPassiveAbility>();
2.  
3. foreach(Type t in FindDerivedTypes(Assembly.GetExecutingAssembly(), typeof(IPassiveAbility)))
4. {
5.   var instance = (IPassiveAbility) Activator.CreateInstance(t);
6.   abilitiesList.Add(instance);
7. }

Note this will only work if you have a parameterless constructor for each of these types (or have not declared any explicit constructors).

 

This works! Many many thanks for your help ^_^

 

To those who might stumble across this problem: take a look at

[SerializeReference]

attribute, this might be something you are searching for
https://docs.unity3d.com/ScriptReference/SerializeReference.html