VBA 32-bit and 64-bit type mismatch

Question

Updated Please see the last part of the question for updates

Full source-code here:

https://www.planet-source-code.com/vb/scripts/ShowCode.asp?txtCodeId=30761&lngWId=1

I have a piece of code that does not work, probably due to 32-bit and 64-bit difference:

Part of the code: (I added the PtrSafe, which I shouldn't for the first one)

Private Declare PtrSafe Function ArrPtr& Lib "msvbvm60.dll" Alias "VarPtr" (ptr() As Any)
Private Declare PtrSafe Sub RtlMoveMemory Lib "kernel32" (dst As Any, src As Any, ByVal nBytes&)

Private Header1(5) As Long
Private Header2(5) As Long
Private SafeArray1() As Integer
Private SafeArray2() As Integer
Private LUT(8482) As Long

Private Sub Class_Initialize()
    Dim i As Long

    ' Set up our template for looking at strings
    Header1(0) = 1              ' Number of dimensions
    Header1(1) = 2              ' Bytes per element (integer = 2)
    Header1(4) = &H7FFFFFFF     ' Array size, 2.1+ billion should cover us

    ' Force SafeArray1 to use Header1 as its own header
    RtlMoveMemory ByVal ArrPtr(SafeArray1), VarPtr(Header1(0)), 4

I googled for sometime, found out that msvbvm60.dll seems to be the old 32-bit VBA and has been replaced with VBA7.dll. Tried to re-register the file as it is in SysWOW64 folder, after which VBE still reports that cannot find this file. So I commented the first line, and changed the last line to:

RtlMoveMemory ByVal VarPtr(SafeArray1), VarPtr(Header1(0)), 4

As I believe ArrPtr is simply VarPtr with an alias.

Now I get a type mismatch error. What I understand is that the code points the header of SafeArray1 to the address of Header1(0). I assume that it means that SafeArray1[0]~SafeArray[9] should contain the info in Header1(0)~Header1(4) as Header1() is Long and SafeArray() is Integer? But shouldn't VarPtr returns Long in 32-bit Office and how come it is possible to use it on an Integer array?

But the point is how to make it run on 64-bit Office. Since VarPtr now returns LongPtr instead of Long, I'm not sure how to modify the code.

Updates I found another piece of code that gives me pointer to an array:

Private Declare PtrSafe Function VarPtrArray Lib "VBE7" Alias _
    "VarPtr" (ByRef Var() As Any) As LongPtr

Then I write a test module:

Private Declare PtrSafe Function VarPtrArray Lib "VBE7" Alias _
        "VarPtr" (ByRef Var() As Any) As LongPtr
Private Declare PtrSafe Sub RtlMoveMemory Lib "kernel32" (dst As Any, src As Any, ByVal nBytes&)
Private Header1(5) As Long
Private SafeArray1() As Integer

Sub test()

    Header1(0) = 1              ' Number of dimensions
    Header1(1) = 2              ' Bytes per element (integer = 2)
    Header1(4) = &H7FFFFFFF     ' Array size, 2.1+ billion should cover us

    RtlMoveMemory ByVal VarPtrArray(SafeArray1), VarPtr(Header1(0)), 4
    Debug.Print SafeArray1(0)

End Sub

But VBE crashes on the RtlMoveMemory line.

Answer 1

The following example should show how to handle Declare statement for 32 and 64 bit versions:

Option Explicit

#If VBA7 Then '64 bit
     Private Declare PtrSafe Function DrawMenuBar Lib "User32" (ByVal hwnd As LongPtr) As LongPtr
#Else '32 bit
    Private Declare Function DrawMenuBar Lib "User32" (ByVal hwnd As Long) As Long
#End If

Answer 2

on the crash issue, I noticed this line:

RtlMoveMemory ByVal VarPtrArray(SafeArray1), VarPtr(Header1(0)), 4

The last argument should be "long" as declared, so try to put "4" in a long variable and pass it to the function. This is my workaround for my own similar case, and hope that helps.