"Object reference not set to an instance of an object"

Hi,

unfortunately I got the following error msg I can't handle at the moment:

"NullReferenceException: Object reference not set to an instance of an object
(wrapper stelemref) object:stelemref (object,intptr,object)
ParticleManager.Start () (at Assets/Scripts/ParticleManager.cs:20)"

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3.  
4. public class ParticleManager : MonoBehaviour {
5.  
6.     public GameObject particle;
7.     public int maxParticles = 1000;
8.  
9.     GameObject[] particleList;
10.  
11.     int nextFreeParticleIdx = 0;
12.  
13.     // Use this for initialization
14.     void Start () {
15.         for (int i = 0; i < 1000; i++) {
16.             GameObject newParticle;
17.             newParticle = Instantiate (particle, transform.position, transform.rotation) as GameObject;
18.             newParticle.GetComponent<Particle>().SetEnabled(false);
19.             newParticle.transform.LookAt(new Vector3(0,0,0));
20.             particleList[i] = newParticle;
21.             Debug.Log("Loading Particle: " + i);
22.         }
23.     }
24.    
25.     // Update is called once per frame
26.     void Update () {  
27.     }
28. }
29.  

this is the line causing the error, but i don't get why!?

Code (CSharp):

1.  
2. particleList[i] = newParticle;
3.  

...if i remove this single line, Unity will create 1000 particles without any problem, but I want to store them (after instancing) in an array....which isn't working.

Anyone can help me?

 

Is it possible that particleList is not initialised?

Try particleList = new GameObject[1000];

 

You never initialize the array. An array expects to be initialized with a predefined size. If you have a collection of variable size, and want to fill it during runtime, use a List<T>, as that can be filled during runtime without needing a set size. Just make sure to initialize it before using it: List<T> list = new List<T>;

https://msdn.microsoft.com/en-us/library/4kf43ys3(v=vs.110).aspx

 

...just for testing purposes: This solution seems to work (for now )! Thx!

But will try Timelog's solution next.

 

I want to add that if you do have a fixed amount of items, like your maxParticles like you have, just use:

Code (CSharp):

1. particleList = new GameObject[maxParticles];

and also make sure to change your for loop:

Code (CSharp):

1. for (int i = 0; i < maxParticles; i++)

This is slightly more performance friendly when you do know the exact maximum size before initializing. In all other cases use a List<T> as a dynamic sized array is less performance friendly.