Function to write an array to an ArrayList - arrays

Question

I am trying to create a VBA function which writes an array to a .NET System.Collections.ArrayList and returns it.
So far I have:
Function arrayToArrayList(inArray As Variant) As ArrayList
'function to take input array and output as arraylist
If IsArray(inArray) Then
Dim result As New ArrayList
Dim i As Long
For i = LBound(inArray) To UBound(inArray)
result.Add inArray(i) 'throws the error
Next i
Else
Err.Raise 5
End If
Set arrayToArrayList = result
End Function
Called with (for example)
Sub testArrayListWriter()
'tests with variant/string array
'intend to pass array of custom class objects
Dim result As ArrayList
Dim myArray As Variant
myArray = Split("this,will,be,an,array",",")
Set result = arrayToArrayList(myArray)
End Sub
But I get the error
Variable uses an Automation type not supported in Visual Basic
Presumably because my array is not the correct type (maybe Variant). However
Dim v As Variant, o As Variant
v = "test_string"
set o = New testClass
result.Add v 'add a string in variant form
result.Add o 'add an object in variant form
raises no errors, so the problem isn't directly to do with the Variant type
What's going on here, and is there any way of writing an array of unspecified type to the ArrayList, or will I have to define the type of inArray?

Answer 1

Change
result.Add inArray(i)
to
result.Add CVar(inArray(i))

Answer 2

Two ways to do this. First is late binding if you don't have a reference to mscorlib.dll. You'll see that I've changed your ArrayList to Object for declaring the function and the return value (retVal). The test sub also declares result as Object. The retVal and result are both late bound to System.Collections.ArrayList. You also need to declare inArray and myArray as dynamic arrays of string. In your example, Split expects returns an array of strings, so you need provide a declared dynamic array of strings. If you wanted to other object types, then you'd pass those declared object types to your function.
Private Function arrayToArrayList(inArray() As String) As Object
'function to take input array and output as arraylist
Dim retVal As Object
Set retVal = CreateObject("System.Collections.ArrayList")
If IsArray(inArray) Then
Dim i As Long
For i = LBound(inArray) To UBound(inArray)
retVal.Add inArray(i)
Next i
Else
Err.Raise 5
End If
Set arrayToArrayList = retVal
End Function
Public Sub testArrayListWriter()
'tests with variant/string array
'intend to pass array of custom class objects
Dim result As Object
Dim myArray() As String
Set result = CreateObject("System.Collections.ArrayList")
myArray = Split("this,will,be,an,array", ",")
Set result = arrayToArrayList(myArray)
End Sub
The second way is to add a reference to mscorlib.dll through the Tools->Reference menu item. When the dialog box appears you'll have to click browse. You'll need to browse to C:\Windows\Microsoft.NET\Framework and then select the folder with the current version of .NET on your machine. In that folder you'll find mscorlib.dll and mscorelib.tlb. Highlight the file ending in .TLB file, click the Open button, on the Tools Reference dialog, click OK.
Now you can use any of the classes in Systems.Collections directly in your code. This is called early binding and looks like this
Private Function arrayToArrayList(inArray() As String) As ArrayList
'function to take input array and output as arraylist
Dim retVal As ArrayList
If IsArray(inArray) Then
Dim i As Long
For i = LBound(inArray) To UBound(inArray)
retVal.Add inArray(i)
Next i
Else
Err.Raise 5
End If
Set arrayToArrayList = retVal
End Function
Public Sub testArrayListWriter()
'tests with variant/string array
'intend to pass array of custom class objects
Dim result As ArrayList
Dim myArray() As String
myArray = Split("this,will,be,an,array", ",")
Set result = arrayToArrayList(myArray)
End Sub

Answer 3

I think the problem is with the assignment of the return value from the Split function to a variable that has not been decalred anywhere.
Try adding:
Dim myArray() as string
inside the testArrayListWriter() procedure.