Il2CppSystem.String static constructor does not initialize Il2CppClassPointerStore<Il2CppSystem.String>.NativeClassPtr #224
Description
You have a Il2CppSystem.Object. You get an exception any time you use TryCast to turn the object into a Il2CppSystem.String or any generic type that contains Il2CppSystem.String.
It turns out you should just never use Il2CppSystem.String at all. Using just string is fine.
I got burned by this issue two times.
One time, I was trying to cast an object (it's a List<string>) out of the object type. I was trying to use TryCast to change the Il2CppSystem.Object into a Il2CppSystem.Collections.Generic.List<Il2CppSystem.String>. But I should have picked the type Il2CppSystem.Collections.Generic.List<string> instead, I just didn't realize it.
The other time was when I was trying to see if an object was a string or not. I have a Il2CppSystem.Object, and want to know if it's a string. If you try to use TryCast to see if it can turn into a Il2CppSystem.String, you get an exception. There is no option to use TryCast with the string type, since it doesn't inherit from Il2CppObjectBase.
Anyway, I was investigating why this was happening and what was going on.
It appears that Il2CppSystem.String has a static constructor that does not initialize Il2CppClassPointerStore<Il2CppSystem.String>.NativeClassPtr. Instead, it writes to Il2CppClassPointerStore<System.String>.NativeClassPtr (the actual string type).
And the static constructor for a generic type such as Il2CppSystem.Collections.Generic.List<Il2CppSystem.String> will try to use the field Il2CppClassPointerStore<Il2CppSystem.String>.NativeClassPtr, but that field is always null, so you get an exception.
To stop the exceptions, the static constructor for Il2CppSystem.String could write to both Il2CppClassPointerStore<Il2CppSystem.String>.NativeClassPtr and Il2CppClassPointerStore<System.String>.NativeClassPtr. But I don't know if that's what's wanted or not.
Maybe put [Obsolete] on the class Il2CppSystem.String to discourage people from trying to use it?
Casting from Il2CppSystem.Object to String is still a bit hairy since there is no TryCastString method. You need to find out if the Type pointer is the type pointer for a string, or call TypeFromPointer and look at the type's name, then use Il2CppStringToManaged.