Cannot step into class / code not executing

I have a MonoBehavior class attached to a model. Inside the Start() method, I instantiate the other class. I've significantly truncated the below code to show only the relevant parts.

Code (CSharp):

1. public class AlienController : MonoBehaviour {
2.     public API api;
3.  
4.     // Use this for initialization
5.     void Start () {
6.         api = new API();
7.         api.OnNewPosts += NewPosts;
8.     }
9.  
10.     void OnSelect()
11.     {
12.         getPosts();
13.     }
14.  
15.     private void getPosts()
16.     {
17.         api.RequestMorePosts();
18.     }
19.  
20.     public void NewPosts(API.Post[] posts)
21.     {
22.         throw new NotImplementedException();
23.     }
24. }

Code (CSharp):

1. public class API {
2.     /* Post class, Response class and subclasses defined here */
3.  
4.     public delegate void NewPosts(Post[] posts);
5.  
6.     private Post[] _posts;
7.  
8.     public event NewPosts OnNewPosts;
9.  
10.     public API()
11.     {
12.     }
13.  
14.     public virtual IEnumerator RequestMorePosts()
15.     {
16.         Debug.Break();
17.         Debug.Log("Requesting new posts");
18.         WWW www = new WWW(BASE_URL);
19.         yield return www;
20.  
21.         Debug.Log("Api returned");
22.         var posts = new ArrayList();
23.         /* Deserialization and translation code here */
24.  
25.         if (OnNewPosts!=null)
26.         {
27.             OnNewPosts((Post[])posts.ToArray(typeof(Post)));
28.         }
29.     }
30. }
31.  

When I set a breakpoint in AlienController.getPosts() it stops execution as expected. api is confirmed to be instantiated. When I try to step into api.RequestMorePosts(), it fails with
Step into: Stepping over non-user code 'API.RequestMorePosts'
Step into: Stepping over non-user code 'API.<RequestMorePosts>d__18..ctor'

My breakpoints inside that class never hit, and my Debug.log / Debug.break statements never hit either. The event also never fires. It is literally giving me nothing to debug with. I'm new to Unity, but am well versed in C#. Any ideas?

 

I'd hazard a guess it's because you are calling RequestMorePosts directly, yet it is a coroutine (you haven't included your import statements so not completely sure, also haven't tried recreating to see what would happen if a coroutine is called directly).
See
https://docs.unity3d.com/ScriptReference/MonoBehaviour.StartCoroutine.html
for how to start a coroutine & see if that makes a difference.

 

Oh, thank you! That has been driving me nuts. I'm still not sure what StartCoroutine actually does, but I know it works now.