C# NullReferenceException with GetComponent issue

Question

I'm having another problem when it comes to GetComponent, as it says it's coming up as a null reference.

I've attempted making the code many different ways but this always pops up.The current test code that I'm applying is:

 public class anotherTest : MonoBehaviour 
 {
     public GameObject Miles;
     // Use this for initialization
     void Start () 
     {
         Miles.GetComponent<test>().Health = 400;
         Debug.Log (Miles.GetComponent<test>().Health);
         
         
     }
     
     // Update is called once per frame
     void Update () 
     {
         if (Input.GetKeyDown(KeyCode.B))
         {
             Miles.GetComponent<test>().Health = Miles.GetComponent<test>().Health + 400;
             Debug.Log (Miles.GetComponent<test>().Health);
             
         }
     
     }
 }

After fighting with GetComponent for awhile, I've turned to this as being one of the only ways I've found that compiles without fail.

The base class that the code is coming from is literally a monobehavior class with just a public int "Health."

The only thing I'm trying to accomplish with this is to see the values every time I hit B to make sure it works. Every time I hit B, though, I get hit with the error. (and also at initialization)

I'm probably missing at least 1 line of code, so could anyone try to point me in the right direction?

Thanks in advanced for helping sort out this issue!

Answer 1

Best Answer

Answer by aldonaletto · Sep 28, 2012 at 06:40 AM

Well, if this compiles ok, the problem probably is the script test.cs not being attached to the object referenced by Miles, or Miles was not assigned in the Inspector.

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Lairinus · Sep 28, 2012 at 06:57 AM 0

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I just assigned both scripts to the same object and now it's compiling-- didn't know that was a necessity lol

Thanks for the help. $$anonymous$$inda odd that it's done that way though.

Originally I had 1 sphere with the test class and 1 cube with the anotherTest class. I originally thought that as long as they derived from $$anonymous$$onoBehaviour, you could pull them from anywhere if they're attached to a gameObject.. together or not

aldonaletto · Sep 29, 2012 at 02:27 PM 0

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GetComponent searches for components attached to a single object only. If you write just GetComponent, this is compiled as this.GetComponent, and the object is the one that holds the script where GetComponent is called. If you write SomeObject.GetComponent, the object is the one referenced by SomeObject. It must be this way, since many objects may have the same component - you must specify in which object to search.

C# NullReferenceException with GetComponent issue

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