Question Resources.LoadAll shows error "InvalidCastException" and "Null Exception" while type casting.

I'm trying to load my scriptable object (LocaleFilesData) from the Resources folder.
Here is the code:

Code (CSharp):

1. UnityEngine.Object[] test1 = Resources.LoadAll("Localization", typeof(LocaleFilesData));
2. Debug.Log($"Resources {test1.Length} {test1[0].GetType()}");
3.  
4. LocaleFilesData[] test2 = (LocaleFilesData[])Resources.LoadAll("Localization", typeof(LocaleFilesData));
5. Debug.Log($"Resources {test2.Length} {test2[0].GetType()}");
6.  
7. LocaleFilesData[] test3 = Resources.LoadAll("Localization", typeof(LocaleFilesData)) as LocaleFilesData[];
8. Debug.Log($"Resources {test3.Length} {test3[0].GetType()}");

Test1 runs properly.
Test2 shows an error: "InvalidCastException: Specified cast is not valid."
Test3 shows another error: "NullReferenceException: Object reference not set to an instance of an object."

If I first save the Object[] and type casting separately like below, it can also run properly.

Code (CSharp):

1. UnityEngine.Object[] test1 = Resources.LoadAll("Localization", typeof(LocaleFilesData));
2. LocaleFilesData data = (LocaleFilesData)test1[0]; // data != null

Could anyone tell me why?

 

You need a cast for every object in the array.

Code (CSharp):

1. // use generic
2. LocaleFilesData[] allLocalFiles = Resources.LoadAll<LocaleFilesData>("Localization");
3.  
4. // array converter
5. LocaleFilesData[] allLocalFiles = Array.ConvertAll(Resources.LoadAll("Localization", typeof(LocaleFilesData)), (i) => (LocaleFilesData)i);
6.  
7. // or linq cast
8. LocaleFilesData[] allLocalFiles = Resources.LoadAll("Localization", typeof(LocaleFilesData)).Cast<LocaleFilesData>().ToArray();

 

@samana1407 Thank you so much for your reply! It works!! Thank you!!!

However, I actually use a similar statement to implement Singleton Scriptable Object for different projects.
So far, everything is good, except for the one I posted in this thread.
Is this due to my luck? Or it's any difference between the two statements (since it is generic?)?

The code is as below:

Code (CSharp):

1. public class SingletonScriptableObject<T> : ScriptableObject where T : ScriptableObject
2. {
3.     private T instance;
4.     public T Instance
5.     {
6.         get
7.         {
8.             if (instance == null)
9.             {
10.                 T[] targets = Resources.LoadAll("", typeof(T)) as T[];
11.  
12.                 if (targets == null || targets.Length <= 0)
13.                 {
14.                     Debug.LogError($"Singleton Scriptable Object not found: {typeof(T).Name}");
15.                 }
16.                 else if (targets.Length > 1)
17.                 {
18.                     Debug.LogError($"Multiple Scriptable Objects found: {typeof(T).Name}");
19.                 }
20.                 else
21.                 {
22.                     instance = (T)targets[0];
23.                 }
24.             }
25.             return instance;
26.         }
27.     }
28.  
29. }

Sorry for keep bothering you Thank you again for your reply!