koobas.hobune.stream
Gameobject not null at start but in function it is.
Dear Unity,
I have a nullpointer exception and am not really sure why I am getting this. I have a script with 2 objects connected to it. Spatula and Fryingpan which I set to nonactive at the initialization of the script start as followed:
if (RecepScenarioObjectHandelerNull())
{
InitializeReceptScenarioObjectHandler();
}
Then it initializes like overe here
void Start () { if (!IfSpatulaAndFryingPanNull()) { Spatula.SetActive(false); FryingPan.SetActive(false); } }
This works perfectly and disabled the game objects right from the start which I want. But when I want to activate the gameobjects for use with the following function I get a nullpointer:
public bool IfSpatulaOrFyingPanActive()
{
if (IfSpatulaAndFryingPanNull())
{
System.Diagnostics.Debug.WriteLine("One of the objects is null");
}
else if (Spatula.activeSelf == true || FryingPan.activeSelf == true)
{
return true;
}
return false;
}
Even if I do not disable the objects in the beginning the debugging shows me that the objects are null and I have no clue why. I do not move to another scene or close a script.
Side note: I added the gameobjects as publics and added the objects in unity as follows:
Does anyone know what the problem could be?
Kr,
Can we see more of your code? Especially your IfSpatualAndFryingPanNull() function
I concur, more code would be helpful. As it is, the only things I can recommend are putting more debugs in, simply saying that "One of the objects is null", doesn't help you figure out which one is null, or why it may be returning true. $$anonymous$$aybe it's a simple logic error. Can't say without anymore code.
@Commoble and @Jicrawley to give it more context. i checked with debugging and see that the objects are not null at start. Then when i call the function with the initialized object (Which is done like this :)
ReceptScenarioObjectHandler receptScenarioObjectHandler = = gameObject.AddComponent<ReceptScenarioObjectHandler>();
in the ReceptScenarioObjectHandler i this start method is the one that sees them active in the beginning and not null but not afterwards when i for example press a button and call a function that is supposed to activate them
THe null check code is:
private bool IfSpatulaAndFryingPanNull()
{
return Spatula == null || FryingPan == null;
}
Is this helpfull enough?
You're adding in another component of the same type, that's where the issue is. When you add in a new component, all the values inside that class are initialised to the default. In this case, the default values for Spatula and FryingPan are indeed null, hence your null reference exception. The one that you assigned in the editor has all of the references already sorted out, hence why they aren't null when the component starts. You need to use the gameobjects Get Component method to get the component instance, not Add Component. This instance will be the one you tweaked in the editor, the one that is on the gameobject.
@jjcrawley you just fixed it for me and explained it perfectly can you answer it seperatly so i can mark it as answer?
There you go. Glad that I was able to help. Best of luck with your game.
Hi! Just a small thing, but the logic of your method for checking for nulls is named using 'and':
however, your code is using the 'or' test, not 'and':IfSpatulaAndFryingPanNull()
return Spatula == null || FryingPan == null;
This could cause some confusion if the two aren't in agreement ;)
