Passing an array of Arguments to CallByName VBA

Question

I'm using callByName I VBA to dynamically call different methods of a class. Depending on the method, I will have a different number of arguments which will be held in an array. Unfortunately CallByName accepts a param array, therefore it's not straightforward to pass a variable number. Is there a way around this, I found a solution using the Type Information Library but this does not seem to work on VBA even though I have added it as a reference. Below is an illustration of what I want

 Public Sub Initialize_Object(ByRef TaskObject, Task_Collection)

 Dim Task_begin As Variant, Method_Parameters As Variant

 Task_begin = Task_Collection("Method")

 CallByName TaskObject, Task_begin, VbMethod, Method_Parameters

Answer 1

You could use CallByName with an array as argument by changing the method signature :

#If VBA7 Or Win64 Then
  Private Declare PtrSafe Function rtcCallByName Lib "VBE7.DLL" ( _
    ByVal Object As Object, _
    ByVal ProcName As LongPtr, _
    ByVal CallType As VbCallType, _
    ByRef args() As Any, _
    Optional ByVal lcid As Long) As Variant
#Else
  Private Declare Function rtcCallByName Lib "VBE6.DLL" ( _
    ByVal Object As Object, _
    ByVal ProcName As Long, _
    ByVal CallType As VbCallType, _
    ByRef args() As Any, _
    Optional ByVal lcid As Long) As Variant
#End If

Public Function CallByName2(Object As Object, ProcName As String, args() As Variant)
   AssignResult CallByName2, rtcCallByName(Object, StrPtr(ProcName), VbMethod, args)
End Function

Private Sub AssignResult(target, result)
  If VBA.IsObject(result) Then Set target = result Else target = result
End Sub

Here is a usage example:

Sub UsageExample()
  Dim obj As Object, arguments()

  Dim obj As New Class1
  arguments = Array(1, 3)

  CallByName2 obj, "MyMethod", arguments
End Sub