Coroutine trouble (stop coroutine with a condition)

Hello All,

My problem is, that I have a simple coroutine eg. like this one:

Code (csharp):

1.     public IEnumerator Test()
2.     {
3.         while (???)
4.         {
5.             Debug.Log("coroutine");
6.             yield return null;
7.         }
8.     }

I have an update cycle as well:

Code (csharp):

1.     private void Update()
2.     {
3.         if (Input.GetMouseButtonDown(0))
4.         {
5.             StartCoroutine(Test());
6.         }
7.     }

So currently as you see it's working, when I push the mousebutton down, the above coroutine will be started. But I'm in trouble because I would like to solve, that if I push the button down, the actually running coroutine should be stopped before running the coroutine again.

I know, that there is a stopcoroutine method in Unity, but I think, the concept of the coroutines is the conditions, and not the forced stop.

Thank you

 

Here are two ways:

1. If this is the only coroutine for this MonoBehaviour, use StopAllCoroutines(). Example:

Code (csharp):

1. private void Update()
2. {
3.     if (Input.GetMouseButtonDown(0))
4.     {
5.         StopAllCoroutines();
6.         StartCoroutine(Test());
7.     }
8. }

The downside is that this stops the coroutine immediately. If the coroutine needs to run some cleanup before exiting, you shouldn't use this.


2. Or use a flag. Here's one suggestion:

Code (csharp):

1. private enum CoroutineState = { Inactive, Active, Reset };
2. private CoroutineState coroutineState = CoroutineState.Inactive;
3.  
4. private void Update()
5. {
6.     if (Input.GetMouseButtonDown(0))
7.     {
8.         switch (coroutineState) {
9.         case CoroutineState.Inactive: StartCoroutine(Test());
10.         case CoroutineState.Active: coroutineState = CoroutineState.Reset; break;
11.         default: break;
12.         }
13.     }
14. }
15.  
16. public IEnumerator Test()
17. {
18.     coroutineState = CoroutineState.Active;
19.     while (???)
20.     {
21.         Debug.Log("coroutine");
22.         if (coroutineState == CoroutineState.Reset)
23.         {
24.             StartCoroutine(Test());
25.             yield break;
26.         }
27.         yield return null;
28.     }
29.     coroutineState = CoroutineState.Inactive;
30. }

Don't use StopCoroutine(). It only accepts a string, which means you have to invoke StartCoroutine with a string name (e.g., StartCoroutine("Test")), which is prone to typo bugs.

 

Thank you!

It's working!

 

Happy to help!