Migrating VBA from 32 to 64 bit office fails on "AccessibleObjectFromWindow" in oleacc - excel

Question

I've just moved from office 32 bit to office 64 bit. I have a lot of Outlook macros and Outlook helpfully points out all your VBA code that needs changing, and I've been able to fix most of it. The bit I'm struggling with is the code that I had help writing on one of my last stackexchange posts:
Open attachment in excel window and copy to open workbook
The code is supposed to find an excel window with my spreadsheet in it so I can mess about with it in the remainder of the code. Just to recap, the below works in 32 bit:
Option Explicit
Private Declare Function FindWindowEx Lib "user32" Alias "FindWindowExA" _
(ByVal hWnd1 As Long, ByVal hWnd2 As Long, ByVal lpsz1 As String, _
ByVal lpsz2 As String) As Long
Private Declare Function GetDesktopWindow Lib "user32" () As Long
Private Declare Function AccessibleObjectFromWindow& Lib "oleacc" _
(ByVal hwnd&, ByVal dwId&, riid As GUID, xlWB As Object)
Private Const OBJID_NATIVEOM = &HFFFFFFF0
Private Type GUID
lData1 As Long
iData2 As Integer
iData3 As Integer
aBData4(0 To 7) As Byte
End Type
Sub Sample()
Dim Ret
Dim oXLApp As Object, wb As Object
Dim sPath As String, sFileName As String, SFile As String, filewithoutExt As String
Dim IDispatch As GUID
sPath = "C:\Users\Chris\Desktop\"
sFileName = "Data.xlsx": filewithoutExt = "Data"
SFile = sPath & sFileName
Ret = IsWorkBookOpen(SFile)
'~~> If file is open
If Ret = True Then
Dim dsktpHwnd As Long, hwnd As Long, mWnd As Long, cWnd As Long
SetIDispatch IDispatch
dsktpHwnd = GetDesktopWindow
hwnd = FindWindowEx(dsktpHwnd, 0&, "XLMAIN", vbNullString)
mWnd = FindWindowEx(hwnd, 0&, "XLDESK", vbNullString)
While mWnd <> 0 And cWnd = 0
cWnd = FindWindowEx(mWnd, 0&, "EXCEL7", filewithoutExt)
hwnd = FindWindowEx(dsktpHwnd, hwnd, "XLMAIN", vbNullString)
mWnd = FindWindowEx(hwnd, 0&, "XLDESK", vbNullString)
Wend
'~~> We got the handle of the Excel instance which has the file
If cWnd > 0 Then
'~~> Bind with the Instance
Call AccessibleObjectFromWindow(cWnd, OBJID_NATIVEOM, IDispatch, wb)
'~~> Work with the file
With wb.Application.Workbooks(sFileName)
'
'~~> Rest of the code
'
End With
End If
'~~> If file is not open
Else
On Error Resume Next
Set oXLApp = GetObject(, "Excel.Application")
'~~> If not found then create new instance
If Err.Number <> 0 Then
Set oXLApp = CreateObject("Excel.Application")
End If
Err.Clear
On Error GoTo 0
Set wb = oXLApp.Workbooks.Open(SFile)
'
'~~> Rest of the code
'
End If
End Sub
Private Sub SetIDispatch(ByRef ID As GUID)
With ID
.lData1 = &H20400
.iData2 = &H0
.iData3 = &H0
.aBData4(0) = &HC0
.aBData4(1) = &H0
.aBData4(2) = &H0
.aBData4(3) = &H0
.aBData4(4) = &H0
.aBData4(5) = &H0
.aBData4(6) = &H0
.aBData4(7) = &H46
End With
End Sub
'~~> Function to check if file is open
Function IsWorkBookOpen(FileName As String)
Dim ff As Long, ErrNo As Long
On Error Resume Next
ff = FreeFile()
Open FileName For Input Lock Read As #ff
Close ff
ErrNo = Err
On Error GoTo 0
Select Case ErrNo
Case 0: IsWorkBookOpen = False
Case 70: IsWorkBookOpen = True
Case Else: Error ErrNo
End Select
End Function
There seems to be one line failing in the below, which is only invoked when the excel file you're looking is open, and in the 32 bit version it sets 'wb' to the application that's got it open.
I've commented the broken line:
Option Explicit
Private Declare PtrSafe Function FindWindowEx Lib "user32" _
Alias "FindWindowExA" (ByVal hWnd1 As LongPtr, ByVal hWnd2 As LongPtr, _
ByVal lpsz1 As String, ByVal lpsz2 As String) As LongPtr
Public Declare PtrSafe Function GetDesktopWindow Lib "user32" () As LongPtr
Private Declare Function AccessibleObjectFromWindow& Lib "oleacc" _
(ByVal hwnd&, ByVal dwId&, riid As GUID, xlWB As Object)
Private Const OBJID_NATIVEOM = &HFFFFFFF0
Private Type GUID
lData1 As LongPtr
iData2 As Integer
iData3 As Integer
aBData4(0 To 7) As Byte
End Type
Sub Sample()
Dim Ret
Dim oXLApp As Object, wb As Object
Dim sPath As String, sFileName As String, SFile As String, filewithoutExt As String
Dim IDispatch As GUID
sPath = "C:\Users\Chris\Desktop\"
sFileName = "Data.xlsx": filewithoutExt = "Data"
SFile = sPath & sFileName
Ret = IsWorkBookOpen(SFile)
'~~> If file is open
If Ret = True Then
Dim dsktpHwnd As LongPtr, hwnd As LongPtr, mWnd As LongPtr, cWnd As LongPtr
SetIDispatch IDispatch
dsktpHwnd = GetDesktopWindow
hwnd = FindWindowEx(dsktpHwnd, 0&, "XLMAIN", vbNullString)
mWnd = FindWindowEx(hwnd, 0&, "XLDESK", vbNullString)
While mWnd <> 0 And cWnd = 0
cWnd = FindWindowEx(mWnd, 0&, "EXCEL7", filewithoutExt)
hwnd = FindWindowEx(dsktpHwnd, hwnd, "XLMAIN", vbNullString)
mWnd = FindWindowEx(hwnd, 0&, "XLDESK", vbNullString)
Wend
'~~> We got the handle of the Excel instance which has the file
If cWnd > 0 Then
'~~> Bind with the Instance
'!!!!!!!!!!this next line does nothing!!!!!!!
Call AccessibleObjectFromWindow(cWnd, OBJID_NATIVEOM, IDispatch, wb)
'~~> Work with the file
With wb.Application.Workbooks(sFileName)
'
'~~> Rest of the code
'
End With
End If
'~~> If file is not open
Else
On Error Resume Next
Set oXLApp = GetObject(, "Excel.Application")
'~~> If not found then create new instance
If Err.Number <> 0 Then
Set oXLApp = CreateObject("Excel.Application")
End If
Err.Clear
On Error GoTo 0
Set wb = oXLApp.Workbooks.Open(SFile)
'
'~~> Rest of the code
'
End If
End Sub
Private Sub SetIDispatch(ByRef ID As GUID)
With ID
.lData1 = &H20400
.iData2 = &H0
.iData3 = &H0
.aBData4(0) = &HC0
.aBData4(1) = &H0
.aBData4(2) = &H0
.aBData4(3) = &H0
.aBData4(4) = &H0
.aBData4(5) = &H0
.aBData4(6) = &H0
.aBData4(7) = &H46
End With
End Sub
'~~> Function to check if file is open
Function IsWorkBookOpen(FileName As String)
Dim ff As Long, ErrNo As Long
On Error Resume Next
ff = FreeFile()
Open FileName For Input Lock Read As #ff
Close ff
ErrNo = Err
On Error GoTo 0
Select Case ErrNo
Case 0: IsWorkBookOpen = False
Case 70: IsWorkBookOpen = True
Case Else: Error ErrNo
End Select
End Function

Answer 1

You've declared AccessibleObjectFromWindow() using shorthand notation which uses 32bit data types, try changing to:
Private Declare PtrSafe Function AccessibleObjectFromWindow Lib "oleacc" _
(ByVal hwnd As LongPtr, ByVal dwId As LongPtr, riid As GUID, xlWB As Object) As LongPtr

Answer 2

Finally found an answer here:
https://stackoverflow.com/a/28504836/317958
So I made two mistakes, first I was over-enthusiastic with changes:
Private Type GUID
lData1 As LongPtr
iData2 As Integer
iData3 As Integer
aBData4(0 To 7) As Byte
End Type
Should remain:
Private Type GUID
lData1 As Long
iData2 As Integer
iData3 As Integer
aBData4(0 To 7) As Byte
End Type
And the declaration should be:
Private Declare PtrSafe Function AccessibleObjectFromWindow Lib "oleacc" (ByVal Hwnd As LongPtr, ByVal dwId As LongPtr, ByRef riid As GUID, ByRef ppvObject As Object) As LongPtr