Excel – Making sure public VBA methods don’t show up in the list of Excel macros

excelvba

In Excel VBA (2003), I've noticed that any Public or Friend Sub method in either a module or ThisWorkbook that doesn't have any arguments will show up as a Macro that can be run by the user. I.e. when the user goes to Tools –> Macro –> Macros… (or Alt+F8) the method will show up in the list that can be run.

For sanity's sake (organization, maintenance, etc) I do need to separate the code into modules. I'm hoping to find a non-hacky way to hide some methods from the user, but still allow them to be visible to other code modules. Note that all the code is contained within the same application, so no external code is called.

My current work-around is to use Functions that return a boolean instead of Subs, and just ignore the return value. eJames suggested the option of using an optional argument in the Sub, which will also hide the method from the list of macros.

Neither of these feel quite right, however, so any advice about how to structure a non-trivial Excel VBA application would be much appreciated.

Best Answer

Add the following to the top of your module:

Option Private Module

From MSDN:

When a module contains Option Private Module, the public parts, for example, variables, objects, and user-defined types declared at module level, are still available within the project containing the module, but they are not available to other applications or projects.

How it works

I will try my best to explain how it works - please excuse my English.

The VBE will call a system function to create the password dialog box.
If user enters the right password and click OK, this function returns 1. If user enters the wrong password or click Cancel, this function returns 0.
After the dialog box is closed, the VBE checks the returned value of the system function
if this value is 1, the VBE will "think" that the password is right, hence the locked VBA project will be opened.
The code below swaps the memory of the original function used to display the password dialog with a user defined function that will always return 1 when being called.

Using the code

Please backup your files first!

Open the file(s) that contain your locked VBA Projects

Create a new xlsm file and store this code in Module1

code credited to Siwtom (nick name), a Vietnamese developer

Option Explicit

Private Const PAGE_EXECUTE_READWRITE = &H40

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

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

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

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

Private Declare 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

Private Function MyDialogBoxParam(ByVal hInstance As Long, _
        ByVal pTemplateName As Long, ByVal hWndParent As Long, _
        ByVal lpDialogFunc As Long, ByVal dwInitParam As Long) As Integer
    If pTemplateName = 4070 Then
        MyDialogBoxParam = 1
    Else
        RecoverBytes
        MyDialogBoxParam = DialogBoxParam(hInstance, pTemplateName, _
                           hWndParent, lpDialogFunc, dwInitParam)
        Hook
    End If
End Function

Paste this code under the above code in Module1 and run it

Sub unprotected()
    If Hook Then
        MsgBox "VBA Project is unprotected!", vbInformation, "*****"
    End If
End Sub

Come back to your VBA Projects and enjoy.

Excel – Is it possible to force Excel recognize UTF-8 CSV files automatically

Alex is correct, but as you have to export to csv, you can give the users this advice when opening the csv files:

Save the exported file as a csv
Open Excel
Import the data using Data-->Import External Data --> Import Data
Select the file type of "csv" and browse to your file
In the import wizard change the File_Origin to "65001 UTF" (or choose correct language character identifier)
Change the Delimiter to comma
Select where to import to and Finish

This way the special characters should show correctly.

Best Answer

Related Solutions

Excel – way to crack the password on an Excel VBA Project

How it works

Using the code

Excel – Is it possible to force Excel recognize UTF-8 CSV files automatically

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