Deserialise JSON message of two types - json

Question

I try to consume web service returning JSON messages. Each method returns relevant JSON message (typically an array) or JSON error message (not an array).
Examples of UserList and Error messages:
[
{
"id":1,
"login":"john1",
"full_name":"John Smith"
},
{
"id":2,
"login":"anne",
"full_name":"Anne Steward"
}
]
{
"success":false,
" message":"Unknown login"
}
Because code does not know which message to expect, I have created two classes where UserList inherits from BaseResponse (an error message class). I have used inheritance, as all other methods like GetCarList, etc. are suitable of returning an error message as well. So no need to declare error fields multiple times. That had to be smart - I will always get or UserList fields or error message fields in the same object.
Public Class BaseResponse
Public success As Boolean
Public message As String
End Class
Public Class UserListResponse
Inherits BaseResponse
Public id As Integer
Public login As String
Public full_name As String
End Class
The problem is, that UserListResponse JSON message is an array, while ErrorMessage JSON is not an array. So deserialising will work when JSON will be UserList but will not work when JSON will be an error message:
JsonConvert.DeserializeObject(Of List(Of UserListResponse))(ReceivedJSONMessage)
Any ideas how to tackle this in smart way?

Answer 1

If you are certain that both of your return classes are working for deserializing the json correctly you just need in essence: "Am I a list or a string?" to ask for one path or the other.
EDIT 8-30
Okay so I missed that you do not KNOW till after it was executed, my bad. You can do the logic inside of Sub Routine instead of a Function then that does the logic directly on examining a generic object passed instead. Similar to this.
Private Sub DetermineReturn(obj As Object)
If obj.GetType = GetType(String) Then
Console.WriteLine(CType(obj, String))
ElseIf obj.GetType = GetType(List(Of String)) Then
CType(obj, List(Of String)).ForEach(Sub(x) Console.WriteLine(x))
Else
Console.WriteLine("UnKnOwN!1!")
End If
End Sub
Sub Main()
Dim testError = "Oh Shoot Error!"
Dim GoodStuff = New List(Of String)({"I", "am", "a", "list"})
Console.WriteLine("FirstExample")
DetermineReturn(testError)
Console.WriteLine()
Console.WriteLine("SecondExample")
DetermineReturn(GoodStuff)
Console.WriteLine()
Console.WriteLine("ThirdExample")
DetermineReturn(1)
Console.ReadLine()
End Sub
Essentially You would just do the work of either transforming your JSON inside directly of the method 'DetermineReturn' instead of Console.WriteLines. I am interpreting the 'obj' passed in, using reflection to get it's type, and then it is safe to be cast as that type. So you would put the argument of your JSON return in the method like DetermineReturn((YourJSONResult)) and then inside the method do whatever transforms you need on the object.