Resolved Null check in coroutine

I have this coroutine for blinking a sprite, but it contains redundant try-catch sections. How can I simplify it?
Using "if (sprite != null)" resulted in a null pointer exception if the object was destroyed during the null check and value assignment.

Code (CSharp):

1.  
2.     private static IEnumerator BlinkCoroutine(SpriteRenderer sprite, float frequency, bool[] flag)
3.     {
4.         while (flag[0])
5.         {
6.             try
7.             {
8.                 sprite.enabled = !sprite.enabled;
9.             }
10.             catch (NullReferenceException)
11.             {
12.                 yield break;
13.             }
14.             yield return new WaitForSeconds(frequency);
15.         }
16.  
17.         try
18.         {
19.             sprite.enabled = true;
20.         }
21.         catch (NullReferenceException)
22.         {
23.             yield break;
24.         }
25.     }

 

You can not destroy an object during the null check or during an assignment. You can only work with GameObjects and components on the main thread and coroutines only run on the main thread. So if you do a null check right before assigning a value to the object, it can not magically turn to a fake null object in between.

 

Sorry, I mistook the name of the error, actual error was 'MissingReferenceException'.

 

Can't you just ...?

Code (CSharp):

1. private static IEnumerator BlinkCoroutine(SpriteRenderer sprite, float frequency, bool[] flag) {
2.   if(flag[0]) {
3.     if(sprite) sprite.enabled = !sprite.enabled;
4.     yield return new WaitForSeconds(frequency);
5.   }
6. }

You need to stop the coroutine elsewhere if that's a concern, but it shouldn't crash.

The biggest complication about this is trying to squeeze everything through coroutines.
They are not your paracetamol. Heck not even paracetamol is paracetamol. It's actually highly toxic.

If I were you, I would build a dedicated time measuring thing and hook events to it, making sure I have ample room for growth, sorting weird edge-cases, and access to features like being able to mute or isolate this behavior this to help me test things in the long run etc.

 

Why are you writing code to blink something? Have you considered using an animation?

 

Thank you for the suggestion. I remade it with animation and it seems to work.