Retrieving component class from object in C#

Question

I have a base abstract class Component and a class GameObject with a list of Components. I want to retrieve a component from that list but I can't figure out how.

public T GetComponent<T>() {
    foreach (Component Component in Components) // Components is a list
       if (Component is T)
           return (T)(object)Component;

    return (T)(object)null;
}

Can you provide us with more details? `GetComponent` is your code? It resides in class `GameObject`? The code I read simply means "return the component with the class of type T" — Guillaume S., Jan 11 '20 at 18:55
GetComponent is a method inside of class GameObject. The current code seems to not be working, as I get an Object reference not set to an instance of an object error when I call it — imtouchk, Jan 11 '20 at 18:59

score 1 · Answer 1 · answered Jan 11 '20 at 19:04

1

Your code can be simplified using Linq to this line:

public T GetComponent<T>()
{
    return this.Components.OfType<T>().FirstOrDefault(); 
}

If that throws a NullReferenceException, then Components is null and you need to initialize it.

answered Jan 11 '20 at 19:04

nvoigt

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It still throws a `NullReferenceException`, but `Components` is not null. The function stopped working since I started using Json.NET to save and load a `Scene` class which has all the GameObjects stored within – imtouchk Jan 11 '20 at 19:08
I guess you will need to use a debugger to solve that problem. See https://stackoverflow.com/questions/4660142/what-is-a-nullreferenceexception-and-how-do-i-fix-it – nvoigt Jan 11 '20 at 19:39

Retrieving component class from object in C#

1 Answers1