C# creating a class derived from an abstract and singleton class

Question

public class Singleton<T> : MonoBehaviour where T : MonoBehaviour
{
    // this is my singleton class
}

public abstract class A : Singleton<A>
{
    // this is my base abstract class. 
}

public B : A
{
    // I want this class to be derived from A, also to derive from Singleton and MonoBehaviour
}``

Since c# does not support multiple inheritance. I am trying to make a class which is derived from class A and singleton class. When I call an instance of B. It creates an instance of A and that gives a null exception. Is there a solution for this or do I have to use interface ? Thanks in advance.

Answer 1

The first question is : What do you want to share between this classes ?

Waiting this answer, I will try to give you a generic explanation with as much detail as possible.

1 - Sharing only methods

If you want to share only methods, the best practice is to use Interfaces to split your logic as you want and give it to concrete classes :

public interface IInterface1{
//some methods
}


public interface IInterface2{
//some methods
}

public class MyClass : IInterface1, IInterface2{

}

MyClass can be abstract if you want and you can put some methods as virtual to override them if you want too

2 - Sharing methods and properties

You will do it from the same way, but the Interfaces need to be added to the correct class

 public interface IInterface1{
    //some methods
    }


public interface IInterface2{
//some methods
}

public abstract class MyAbstractClass {
//some methods and properties
}

 public class MyClass : MyAbstractClass, IInterface1, IInterface2{

    }

You can add the interfaces to MyAbstractClass instead of MyClass , it depends your architecture and your needs

3 - Singleton

For the singleton, as say in the comments, this is only a way to gain global accessibility, so you need to do it in your "last" class, here MyClass

I Hope I expressed myselft enought correctly for this explanation and I hope this answer will help you.