Using generics as variable types in Unity

Question

. 。 This would be used in place of ButtonManager in the following code, Is this possible? Could I use generics to accomplish this? I wish to do this so I can reuse this method for a variety of Component types, vice having to make a method per component type.

private GameObject[] FindInActiveObjectsByType()
    {
        List<GameObject> validTransforms = new List<GameObject>();
        ButtonManager[] objs = Resources.FindObjectsOfTypeAll<ButtonManager>() as ButtonManager[];
        for (int i = 0; i < objs.Length; i++)
        {
            if (objs[i].hideFlags == HideFlags.None)
            {
                objs[i].gameObject.GetComponent<ButtonManager>().ConfigureInteractives();
                validTransforms.Add(objs[i].gameObject);
            }
        }
        return validTransforms.ToArray();
    }

Answer 1

You are already using the generic overload Resources.FindObjectsOfTypeAll<T>() which always returns T[]

In order to make the rest (eg GetComponent ) work you only have to make sure that T is always of type Component so you would do

public GameObject[] YourMethod<T>() where T : Component
{
    List<GameObject> validTransforms = new List<GameObject>();
    T[] objs = Resources.FindObjectsOfTypeAll<T>();
    for (int i = 0; i < objs.Length; i++)
    {
        if (objs[i].hideFlags == HideFlags.None)
        {
            //objs[i].gameObject.GetComponent<T>().ConfigureInteractives();
            validTransforms.Add(objs[i].gameObject);
        }
    }
    return validTransforms.ToArray();
}

---

Note however that ConfigureInteractives() seems to be specificly related to your ButtonManager and will throw an exception since it is not part of Component .

So in case you need this for other stuff inheriting from ButtonManager then simply exchange the Component with ButtonManager in

public void YourMethod<T>() where T : ButtonManager

---

How could I check the passed in Type

There are multiple ways. You could eg check the exact passed type using

if(typeof(T) == typeof(ButtonManager)) (objs[i].gameObject.GetComponent<T>() as ButtonManager).ConfigureInteractives();

but then you could also simply g back to using

if(typeof(T) == typeof(ButtonManager)) objs[i].gameObject.GetComponent<ButtonManager>().ConfigureInteractives();

or you could use maybe typeof(T).IsSubclassOf(typeof(ButtonManager)) for also matching inherited types.

Answer 2

Sure, you can do the following:

public void YourFunction<T>() where T : Component
{
    T component = gameObject.GetComponent<T>();
}