Question

I’m working on a Unity3d game using C#, and we have a lot of situations where we need to access a particular member (say, int health) of a GameObject. We do this using code like:

GameObject obj;
if(obj.GetComponent<Player>() != null) {
    obj.GetComponent<Player>().health--;
}
else if(obj.GetComponent<Robot>() != null) {
    obj.GetComponent<Robot>().health--;
}
// more painful code

What I’d like to do is have all such classes implement an interface like IHealth, and then do obj.GetComponent<IHealth>().health--;. Is this possible, though? I’ve looked around and it seems like I can’t use an interface as a type parameter.

Answer 1

Why not just have a component Health. Then attach that to your GameObject, have a RequiresComponent annotation on any scripts that need health, then get it by GetComponent<Health>(); (cache it inside the same-object scripts in a private variable)

If you have multiple ‘stats’ that are always together, you could make it easier like

public class Status : MonoBehaviour
{
    public float health;
    public float armor;
}

I’ve found with unity, this is a surprisingly common ‘problem’. Not sure if it’s a problem because this thinking can really help with some problems…