How do I enable and disable objects with a certain tag in C#?

Question

I have a script that is supposed to find every active object with a certain tag and on the push of a button enable and disable it's meshrenderer and collider. but the script only tries to enable and disable the previous on the object the script is attached to. what am i doing wrong and is there any feasible way to do this?

I've checked all tags, but the script keeps trying to reach this unrelated object. i even tried adding a mesh renderer and a colider. but nothing

here is the script:

private bool on = true;    

public void Update()
{
    GameObject[] gameObjectArray = GameObject.FindGameObjectsWithTag("buildnode");


    if (Input.GetKeyDown("b"))
    {
        on = !on;
    }



    if (on == false)
    {
        foreach (GameObject go in GameObject.FindGameObjectsWithTag("buildnode"))
        {
            go.GetComponent<MeshRenderer>().enabled = false;
            go.GetComponent<Collider>().enabled = false;
        }
    }

    if (on==true)
    {
        foreach (GameObject go in GameObject.FindGameObjectsWithTag("buildnode"))
        {
            go.GetComponent<MeshRenderer>().enabled = true;
            go.GetComponent<Collider>().enabled = true;
        }
    }
}

Thank you and have a good day.

Answer 1

It seems like this code should work, you probably need to add checks to make sure the gameObject is active, and has the components you want to work with. Do this with a LINQ where clause like this:

  GameObject[] gameObjectArray = GameObject.FindGameObjectsWithTag("buildnode")
     .Where(go => go.activeInHierarchy && 
                  go.GetComponent<MeshRenderer>() && 
                  go.GetComponent<Collider>())
     .ToArray();

then you can really simplify the if statements by just removing them:

foreach(var go in gameObjectArray){
     go.GetComponent<MeshRenderer>().enabled = on;
     go.GetComponent<Collider>().enabled = on;
}

Answer 2

You cant find Disabled Objects with GameObject.FindGameObjectsWithTag("buildnode")

you can find object you want using:

  GameObject[] items=     Resources.FindObjectsOfTypeAll(typeof(UnityEngine.GameObject)) as GameObject[];
  GameObject obj = items.FirstOrDefault(x=>x.tag=="mytag");

Answer 3

Iterating on the answer by Glenn van Acker.

When you are already using a LINQ chain, then you can just as well avoid the duplicate calls to GetComponent by using the LINQ .Select to transform a gameObject into an anonymous class (aka "tuple") with two variables meshRenderer and collider. And you can avoid the conversion to an array by feeding the results of the LINQ query directly into a a foreach loop:

    foreach(var tuple in 
        GameObject.FindGameObjectsWithTag("Respawn")
        .Where(go => go.activeInHierarchy)
        .Select(go => new {
            meshRenderer = go.GetComponent<MeshRenderer>(),
            collider = go.GetComponent<Collider>()
        })
        .Where(tuple => tuple.meshRenderer &&
                        tuple.collider)) 
    {
        tuple.meshRenderer.enabled = true;
        tuple.collider.enabled = true;
    }