Unity Update Text on Gameobject initiated from script from other Gameobject

Question

I am developing for the HoloLens and I Made an object that follows me around. This Gameobject is actually an UI Canvas with text in it which I set like this because i want to keep the original object as well. (Just like in the MS example):

 /// <summary>
/// The object to tag along set in the unity editor
/// </summary>
public GameObject ObjectToTagAlong;

/// <summary>
/// The instantiated object to tag along that follows you around.
/// </summary>
private GameObject instantiatedObjectToTagAlong;

 this.instantiatedObjectToTagAlong = GameObject.Instantiate(this.ObjectToTagAlong);

this instantiatedObject tags along just fine but now I want to update the Text on instantiatedObjectToTagAlong but have no idea how to do this. (I can very easily update the text on the 1st object but i want to do it this way)

Does anyone know how to update the text on a gameobject that is initiated from another GameObject?

Are you aware of the GetComponent() method? It sounds like what you need, unless you're actually trying to do something other than modifying a Text component on the instantiated GameObject. — Serlite
Hhmm would that actually be able to filter for a specific text? For example if i have a textfield called SuperText 2 Can i say Text SuperText2 << (Then assign the object in Unity) Text newUpdatedText= gameObject.GetComponent(typeof(SuperText2 )) as SuperText2; And then newUpdatedText.Text = "New Text" — Tvt
Er...if your component is of type SuperText2, then you might be able to do that - it'd clear up any ambiguity if you included a screenshot of your object hierarchy, and indicate what you're trying to modify. — Serlite
Hey Serlite see my comment at Avariant. Maybe that hierarchy image will help. — Tvt

avariant avariant · Accepted Answer · 2017-04-06T21:36:20

To build on what Serlite commented with, you need to use GetComponent in combination with another script.

public class MyTextUpdater: MonoBehavior
{
public Text SuperText2;
}

Apply MyTextUpdater to your ObjectToTagAlong prefab (or GameObject if not a prefab) and, in the editor, set the value of SuperText2 to the Text object you want to update (typically this is a child of the ObjectToTagAlong GameObject).

Now anytime you want to update that Text object on your instance, instantiatedObjectToTagAlong, you can do this:

MyTextUpdater text = instantiatedObjectToTagAlong.GetComponent<MyTextUpdate>();
if (text!=NULL && text.SuperText2!=NULL) { /*do whatever you need to do on the text.SuperText2 object*/ }

EDIT: When Unity instantiates a copy of a GameObject, it makes a "deep" copy of sorts, meaning that the copy will have the exact same structure of child GameObjects.

Original                                Copy
- Child A                               - Child A (copy)
- Child B              Instanitate =>   - Child B (copy)
- - Grandchild A                        - - Grandchild A (copy)

Each child is instantiated with it's own new copy. On top of that, if Original has a MonoBehavior script that points to one of it's children (or grandchildren etc), Copy will have a script that points to the appropriately copied child.

MyTextUpdater [Original]                 MyTextUpdater [Copy]
- SuperText2 = Child B           =>       - SuperText2 = Child B (copy)

Regarding the question of why have the extra script (the MyTextUpdater script):

Original is just a GameObject. In the editor you can see it has children, but that does not represent a class. You can not do something like this in a script:

Original.ChildB.Text = "Hello World!";

in the same way, you can't do this:

Copy.ChildB.Text = "Hello Copy World!";

You could create code to iterate through all the children of the GameObject looking for a child with the correct name ("ChildB"), but that is inefficient and probably bad programming. The better way is to create a script class that actually does give you access to the child as a field in that class. And that is where the MyTextUpdater script comes in.

This would be invalid:

GameObject Copy = Instantiate(Original);
Copy.SuperText2.Text = "Some text here";

Copy does not have a field or method called SuperText2, or ChildB, or whatever you would call it. But you could do this:

GameObject Copy = Instantiate(Original);
MyTextUpdater mtu = Copy.GetComponent<MyTextUpdater>();
mtu.SuperText2.Text = "Some text here";

Assuming of course that you applied the MyTextUpdater script to Original and made the right connections to the child text component.

Unity Update Text on Gameobject initiated from script from other Gameobject

1 Answers