How to hide non-active button?

Questions & Answers
1

Hello.
I am making a game, where the main character can talk with different NPCs.
When he comes close to them (enters trigger collider), “TALK” button appears. When he goes away, the button should disappear.
I made it with button.SetActive(true/false).

using UnityEngine;

public class NPCInteraction : MonoBehaviour {

	public GameObject talkButton;
	
	void OnTriggerEnter2D (Collider2D other) {
		if (other.name == "Player") {
			talkButton.SetActive(true);
			Debug.Log(talkButton.activeSelf);
		}
	}
	void OnTriggerExit2D (Collider2D other) {
		if (other.name == "Player") {
			talkButton.SetActive(true);
			Debug.Log(talkButton.activeSelf);
		}
	}
}

The problem is: button always remains on the screen.

Wat.

As you can see, I made public variable talkButton, so I can just drag any object (not just button) on it to test the script.

The button’s active state changes correctly when I come close and go away, as I can see in debug window Debug.Log(talkButton.activeSelf);

109150-screenshot-from-2018-01-12-21-39-53.png

Also the button’s color changes to gray in hierarchy when it isn’t active.

This is making me go completely bonkers when I try to understand whats going on.
If I place another UI element (dialogue box for example) in the variable, it behaves exactly the same way (remains on the screen), but when I place entire UI (canvas), it works as intended (appears and disappears).

Later I wrote a new simple script to test this and put it into my canvas (UI):

public class UIController : MonoBehaviour {

	public GameObject talkButton;

	void Update () {
		if (Input.GetKeyDown(KeyCode.Space)) {
			talkButton.SetActive(!talkButton.activeSelf);
		}
	}
}

Exactly the same happens. Button remains on the screen. Same happens with any other UI element that I was testing except the entire canvas. Why do elements inside canvas remain there even deactivated? Do i have to make separate canvas for every element if I wanna toggle its state?
I am going to get mad with this.
HALP

2

try to change these things:

  using UnityEngine;
  public class NPCInteraction : MonoBehaviour {
 
     public Button talkButton;
     
     void OnTriggerEnter2D (Collider2D other) 
    {
         if (other.name == "Player") 
         {
             talkButton.gameObject.SetActive(true);
             Debug.Log(talkButton.activeSelf);
         }
     }
     void OnTriggerExit2D (Collider2D other) 
   {
         if (other.name == "Player") 
         {
             talkButton.gameObject.SetActive(false);
             Debug.Log(talkButton.activeSelf);
         }
     }
 }
3

Actually I stopped making the button active/non-active.
Instead I added canvasgroup to button and made it non-interactable, non-blockable and transparent instead of non-active.

It works well and fast, but it requires 3 times more code.