What is the "Type Mismatch Error" I am getting here?

Question

I am Getting the type Mismatch Error in this particular VBA Code, I am Using 64 bit VBA but it was developed for 32 bit. Any Solution, I am new to VBA to I am not able to figure it out. It is showing Error in VarPtr ( Public Fuction Hook() As boolean). I am adding the code below

Option Explicit


Private Const PAGE_EXECUTE_READWRITE = &H40

Private Declare PtrSafe Sub MoveMemory Lib "kernel32" Alias "RtlMoveMemory" _
        (Destination As Long, Source As Long, ByVal Length As Long)

Private Declare PtrSafe Function VirtualProtect Lib "kernel32" (lpAddress As Long, _
        ByVal dwSize As Long, ByVal flNewProtect As Long, lpflOldProtect As Long) As Long

Private Declare PtrSafe Function GetModuleHandleA Lib "kernel32" (ByVal lpModuleName As String) As Long

Private Declare PtrSafe Function GetProcAddress Lib "kernel32" (ByVal hModule As Long, _
        ByVal lpProcName As String) As Long

Private Declare PtrSafe Function DialogBoxParam Lib "User32" Alias "DialogBoxParamA" (ByVal hInstance As Long, _
        ByVal pTemplateName As Long, ByVal hWndParent As Long, _
        ByVal lpDialogFunc As Long, ByVal dwInitParam As Long) As Integer

Dim HookBytes(0 To 5) As Byte
Dim OriginBytes(0 To 5) As Byte
Dim pFunc As Long
Dim Flag As Boolean

Private Function GetPtr(ByVal Value As Long) As Long
    GetPtr = Value
End Function

Public Sub RecoverBytes()
    If Flag Then MoveMemory ByVal pFunc, ByVal VarPtr(OriginBytes(0)), 6
End Sub

Public Function Hook() As Boolean
    Dim TmpBytes(0 To 5) As Byte
    Dim p As Long
    Dim OriginProtect As Long

    Hook = False

    pFunc = GetProcAddress(GetModuleHandleA("user32.dll"), "DialogBoxParamA")


    If VirtualProtect(ByVal pFunc, 6, PAGE_EXECUTE_READWRITE, OriginProtect) <> 0 Then

        MoveMemory ByVal VarPtr(TmpBytes(0)), ByVal pFunc, 6
        If TmpBytes(0) <> &H68 Then

            MoveMemory ByVal VarPtr(OriginBytes(0)), ByVal pFunc, 6

            p = GetPtr(AddressOf MyDialogBoxParam)

            HookBytes(0) = &H68
            MoveMemory ByVal VarPtr(HookBytes(1)), ByVal VarPtr(p), 4
            HookBytes(5) = &HC3

            MoveMemory ByVal pFunc, ByVal VarPtr(HookBytes(0)), 6
            Flag = True
            Hook = True
        End If
    End If
End Function

Answer 1

Varptr will return a "LongPtr" on 64bit Excel and a "Long" on 32bit Excel. your api declarations all use "Long" which is fine in the 32bit world where VarPtr would return a Long, but not in 64bit excel where VarPtr returns a LongPtr. you need to update your api declarations to use LongPtr not Long for 64bit. Example of one of the API calls below:

#If VBA7 Then
    Declare PtrSafe Sub CopyMemory Lib "kernel32.dll" Alias _
            "RtlMoveMemory" (ByRef Destination As LongPtr, ByRef Source As LongPtr, _
            ByVal Length As LongPtr)
#Else
    Declare PtrSafe Sub CopyMemory Lib "kernel32.dll" Alias _
           "RtlMoveMemory" (Destination As Long, Source As Long, _
            ByVal Length As Long)
#End If