Cannot iterate Hashtable in VBA (Excel)

Question

I am using Hashtable (mscorlib.dll referenced). I fill it with data, I can get any item (as long as I convert the request type to exactly same type what\'s stored in hashtab

Answer 1

Actually there is one way to browse a .NET hashtable from VBA :

Dim hash As mscorlib.Hashtable
Set hash = New mscorlib.Hashtable

Call hash.Add("foo", "bar")
Call hash.Add(4, 8)

Dim keys As IEnumerable
Set keys = hash.keys

Dim key As Variant
For Each key In keys

    Dim value As Variant

    value = hash.Item(key)
Next

The main issue being "casting" the return value of the property "Keys" into a IEnumerable before using it in a "for each" loop. VBA can not handle multiple interface inheritance from scratch: you have to cast to the interface the function/property belongs to before you can call it.

Answer 2

VBA cannot handle DictionaryEntry type (element of hashtable) nor ICollection type (that's what .Keys method returns), so only solution was to write my own library.