ACC: Sample Function to Retrieve File Version Information (95/97) (147155)

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Most files used by Windows-based applications contain a version stamp. You can check this version stamp by using Windows API calls within Visual Basic for Applications.

The following example shows you how to create a sample user-defined function to check the version number (if available) of a file.

You may have some Microsoft Windows API functions defined in an existing Microsoft Access library; therefore, your declarations may be duplicates. If you receive a duplicate procedure name error message, remove or comment out the declarations statement in your code.

1. Open the sample database Northwind.mdb.
2. Create a new module, and then add the following code to the Declarations section:

   Type FileInfo
      wLength            As Integer
      wValueLength       As Integer
      szKey              As String * 16
      dwSignature        As Long
      dwStrucVersion     As Long
      dwFileVersionMS    As Long
      dwFileVersionLS    As Long
   End Type
   
   ' NOTE: The following Declare statements are case sensitive.
   
   Declare Function GetFileVersionInfo& Lib "Version" _
        Alias "GetFileVersionInfoA" (ByVal FileName$, _
        ByVal dwHandle&, ByVal cbBuff&, ByVal lpvData$)
   Declare Function GetFileVersionInfoSize& Lib "Version" Alias _
              "GetFileVersionInfoSizeA" (ByVal FileName$, dwHandle&)
   Declare Sub hmemcpy Lib "Kernel32" Alias "RtlMoveMemory" _
              (hpvDest As Any, hpvSource As Any, ByVal cbBytes&)
   					

3. Add the following two functions to the module:

   Function LOWORD(x As Long) As Integer
      LOWORD = x And &HFFFF&
      ' Low 16 bits contain Minor revision number.
   End Function
   
   Function HIWORD(x As Long) As Integer
      HIWORD = x \ &HFFFF&
      ' High 16 bits contain Major revision number.
   End Function
   					

4. Save the module, and then create a new form.
5. Add a text box to the form, and set its Name property to FName.
6. Add a command button to the form, and set the OnClick property of the command button to the following event procedure:

   Dim x As FileInfo
   Dim FileVer As String
   Dim FileName As String
   Dim dwHandle&, BufSize&, lpvData$, R&
   
   '*** Get Version Information If Available ****
   FileVer = ""
   FileName = Me![FName]
   BufSize& = GetFileVersionInfoSize(FileName, dwHandle&)
   If BufSize& = 0 Then
      MsgBox "Invalid File Name or no Version information available"
      Exit Sub
   End If
   lpvData$ = Space$(BufSize&)
   R& = GetFileVersionInfo(FileName, dwHandle&, BufSize&, lpvData$)
   hmemcpy x, ByVal lpvData$, Len(x)
   
   '**** Parse File Version Number ****
   FileVer = Trim$(Str$(HIWORD(x.dwFileVersionMS))) + "."
   FileVer = FileVer + Trim$(Str$(LOWORD(x.dwFileVersionMS))) + "."
   FileVer = FileVer + Trim$(Str$(HIWORD(x.dwFileVersionLS))) + "."
   FileVer = FileVer + Trim$(Str$(LOWORD(x.dwFileVersionLS)))
   
   MsgBox FileVer, 64, "Version of " & FileName
   					

7. To use the function, view the form in Form view and type a valid path and file name in the Fname text box. The following lines are examples of valid paths and file names:

   C:\Windows\System\User32.dll
   C:\Msoffice\Access\Msaccess.exe

8. Click the command button to see the version displayed in a message box.