Client sees only default value of SyncListStruct members

Hi guys!

I am scratching my head over this one, so maybe you can help out. I have a shared "checklist", which can be modified by the users (both clients and servers). Now, adding the items to the SyncListStruct containing the ChecklistItems works wonderfully - the only issue I have is that the clients are unable to read the individual item's values - they're all default (null / false).

This is the shared checklist, whose functions are called via command from the client.

Code (CSharp):

1. public class SharedChecklistState : NetworkBehaviour {
2.  
3. [SyncVar]
4. public CheckListList Checklist;
5. [SyncVar]
6. public float UpdateToken;
7.  
8. private static SharedChecklistState instance;
9. public static SharedChecklistState Instance
10. {
11. get
12. {
13. return instance;
14. }
15. }
16.  
17.  
18. protected virtual void Awake()
19. {
20. if (instance != null)
21. {
22. Debug.LogErrorFormat("Trying to instantiate a second instance of singleton class {0}", GetType().Name);
23. }
24. SharedChecklistState.instance = (SharedChecklistState)this;
25. }
26.  
27. public void AddItem(string text, string GUID)
28. {
29. this.Checklist.Add(new ChecklistItem(GUID, text, false));
30. this.UpdateTimeStamp();
31. }
32.  
33. public void SetItem(bool value, string ID)
34. {
35. ChecklistItem item = this.GetItemByID(ID);
36. if (item.ID != null)
37. {
38. int index = this.Checklist.IndexOf(item);
39. item.done = value;
40. this.Checklist[index] = item;
41. }
42.  
43. this.UpdateTimeStamp();
44. }
45.  
46. public void RemoveItem(string ID)
47. {
48. ChecklistItem item = this.GetItemByID(ID);
49. if (item.ID != null)
50. {
51. this.Checklist.Remove(item);
52. }
53. this.UpdateTimeStamp();
54. }
55.  
56. public void UpdateTimeStamp()
57. {
58. this.UpdateToken = Time.time;
59. }
60.  
61. private ChecklistItem GetItemByID(string ID)
62. {
63. return this.Checklist.First(x => x.ID == ID);
64. }
65. }
66.  
67. [System.Serializable]
68. public struct ChecklistItem
69. {
70.     public string ID { get; set; }
71.     public string text { get; set; }
72.     public bool done { get; set; }
73.  
74.     public ChecklistItem(string ID, string text, bool done)
75.     {
76.         this.ID = ID;
77.         this.text = text;
78.         this.done = done;
79.     }
80. }
81.  
82. public class CheckListList : SyncListStruct<ChecklistItem> { }

Client-sided the change is picked up perfectly fine with the changed update token. They then access the checklist via

foreach (ChecklistItem item in SharedChecklistState.Instance.Checklist) { ... } 

which *does* execute exactly the amount of times there are items in the checklist. But all items (for example when printed out with item.ID / item.text / item.done) are their default values on the client. The server gets the actual values. When adding items client-side, the server still gets the correct value.

What am I missing?

 

You don't declare a syncliststruct as a syncvar, and the documentation shows initializing the syncliststruct when being declared.

https://docs.unity3d.com/ScriptReference/Networking.SyncListStruct_1.html

 

I did try both and either - having it not as Syncvar and initializing it, still same problem

 

Just tested this and you're correct this is a bug. SyncListStruct apparently doesn't work with properties, and the unet weaver fails to catch this.

Simply change your struct to use fields instead and it should work.

Code (CSharp):

1. public struct ChecklistItem
2. {
3.     public string ID;
4.     public string text;
5.     public bool done;
6.     public ChecklistItem(string ID, string text, bool done)
7.     {
8.         this.ID = ID;
9.         this.text = text;
10.         this.done = done;
11.     }
12. }