Problems accessing a method in another script (Object reference not set to an instance of an object)

Archived Forums Questions & Answers
1

Hi everyone,

I know that this question is redundant but I’ve checked almost every post close to my problem without finding a solution so here it is :

I have a GameObject named “Ulysse” with a script named “UlysseMover”. Into this script, I call a public method in a script named “Pilier1” located on a other GameObject named “Pilier1”.
I made the links betweeen scripts so there is no problem on code but when I try to access the method I’ve got an error saying “Object reference not set to an instance of an object”…

==========================================================

UlysseMover.cs

using UnityEngine;
using System.Collections;
    
public class UlysseMover : MonoBehaviour {
    
     //Some code
     //In "public void Update()"

     Pilier1 scrPilier1 = GetComponent<Pilier1>();

     //Code again
     //In "public void Update() too"

     scrPilier1.ActionEffect();
    
     //Still some code
}

============================================================

Pilier1.cs

using UnityEngine;
using System.Collections;

public class Pilier1 : MonoBehaviour {
	
	public void ActionEffect () {
		rigidbody.velocity = new Vector3(0,-10,0);
	}
}

============================================================

Is anyone has the solution ? Thanks !

3

Hello everyone !

@Robertbu : I had already checked that it wasn’t an error of null object etc… but thanks !

@EliteMossy : Thanks ! My problem was solved by searching this way even if I have to add some lines^^

So here is what is working for me :

=========================================================

UlysseMover.cs

public class UlysseMover : MonoBehaviour {
 
 [HideInInspector] private Pilier1 pilierscript;

 public void Update() {
  
  GameObject objetcourant = scrActions.closestObjectActive;

  pilierscript = objetcourant.GetComponent<Pilier1>();
  pilierscript.ActionEffect();
 }

}

==========================================================

Pilier1.cs

public class Pilier1 : MonoBehaviour {

 public void ActionEffect () {

  gameObject.rigidbody.velocity = new Vector3(0,0,-1);

 }
}

==========================================================

Again thanks to the people who answered so quickly ! PROBLEM SOLVED !!!
Have a nice day !

4

Thanks to both of you ! My problem is solved ! Here is the code I add :

UlysseMover.cs

public class UlysseMover : MonoBehaviour {

 private Pilier1 pilierscript;

 public void Update() {

  GameObject objectcourant = scrActions.closestObjectActive;
  pilierscript = objectcourant.GetComponent<Pilier1>();
  pilierscript.ActionEffect();
 }
}

Thanks again for your quick answers ! ==> PROBLEM SOLVED !

2

GetComponent will only get the component on the CURRENT GameObject. If it is on another gameobject, you need to store a reference to the other GameObject or do a search for the GameObject.

Now you can either store it globally, like

using UnityEngine;
using System.Collections;
 
public Pilier1 srcPilier1;

public class UlysseMover : MonoBehaviour {
 
     //Some code
     //In "public void Update()"
 
     //Code again
     //In "public void Update() too"
 
     scrPilier1.ActionEffect();
 
     //Still some code
}

and simply drag the GameObject with the Pilier1 script in the inspector. Or you can simply use Start and do a find. More info is explained here:

http://docs.unity3d.com/Documentation/ScriptReference/index.Accessing_Other_Game_Objects.html

Good luck :slight_smile: