GetFileVersionInfo Function

Declare Function GetFileVersionInfo Lib "version.dll" Alias "GetFileVersionInfoA" (ByVal lptstrFilename As String, ByVal dwHandle As Long, ByVal dwLen As Long, lpData As Any) As Long

Platforms

Windows 95: Supported.
Windows 98: Supported.
Windows NT: Requires Windows NT 3.1 or later.
Windows 2000: Supported.
Windows CE: Not Supported.

Description & Usage

GetFileVersionInfo extracts the version information resource stored inside a 32-bit executable-type file. The version information resource is a series of bytes that is difficult to read directly. Use the VerQueryValue to retrieve the desired pieces of data from the resource.

Return Value

If successful, the function returns a non-zero value. If an error occured, the function returns 0 (use GetLastError to get the error code).

Visual Basic-Specific Issues

None.

Parameters

lpstrFilename: The full path and filename of the file.
dwHandle: Reserved -- set to 0.
dwLen: The size in bytes of the buffer passed as lpData.
lpData: A buffer, such as a byte array, that receives the version information resource of the file.

Example

Display information about the file whose full path and filename is entered into textbox Text1. Display the version number, copyright information, and file description when button Command1 is pressed. To use this example, you obviously have to enter the filename of a 32-bit executable/DLL/etc. into Text1. Obviously, this example requires that you create a text box called Text1 and a command button called Command1.

' This code is licensed according to the terms and conditions listed here.

' Declarations and such needed for the example:
' (Copy them to the (declarations) section of a module.)
Public Declare Function GetFileVersionInfo Lib "version.dll" Alias "GetFileVersionInfoA" _
	(ByVal lptstrFilename As String, ByVal dwHandle As Long, ByVal dwLen As Long, _
	lpData As Any) As Long
Public Declare Function GetFileVersionInfoSize Lib "version.dll" Alias _
	"GetFileVersionInfoSizeA" (ByVal lptstrFilename As String, lpdwHandle As Long) As Long
Public Declare Function VerQueryValue Lib "version.dll" Alias "VerQueryValueA" (pBlock _
	As Any, ByVal lpSubBlock As String, lplpBuffer As Long, puLen As Long) As Long
Public Declare Function lstrcpy Lib "kernel32.dll" Alias "lstrcpyA" (ByVal lpString1 _
	As Any, ByVal lpString2 As Any) As Long
Public Declare Sub CopyMemory Lib "kernel32.dll" Alias "RtlMoveMemory" (Destination As Any, _
	Source As Any, ByVal Length As Long)
Public Type VS_FIXEDFILEINFO
	dwSignature As Long
	dwStrucVersion As Long
	dwFileVersionMS As Long
	dwFileVersionLS As Long
	dwProductVersionMS As Long
	dwProductVersionLS As Long
	dwFileFlagsMask As Long
	dwFileFlags As Long
	dwFileOS As Long
	dwFileType As Long
	dwFileSubtype As Long
	dwFileDateMS As Long
	dwFileDateLS As Long
End Type
Public Const VFT_APP = &H1
Public Const VFT_DLL = &H2
Public Const VFT_DRV = &H3
Public Const VFT_VXD = &H5

' *** Place the following function definitions inside a module. ***

' HIWORD and LOWORD are API macros defined below.
Public Function HIWORD (ByVal dwValue As Long) As Long
	Dim hexstr As String
	hexstr = Right("00000000" & Hex(dwValue), 8)
	HIWORD = CLng("&H" & Left(hexstr, 4))
End Function
Public Function LOWORD (ByVal dwValue As Long) As Long
	Dim hexstr As String
	hexstr = Right("00000000" & Hex(dwValue), 8)
	LOWORD = CLng("&H" & Right(hexstr, 4))
End Function

' This nifty subroutine swaps two byte values without needing a buffer variable.
' This technique, which uses Xor, works as long as the two values to be swapped are
' numeric and of the same data type (here, both Byte).
Public Sub SwapByte (byte1 As Byte, byte2 As Byte)
	byte1 = byte1 Xor byte2
	byte2 = byte1 Xor byte2
	byte1 = byte1 Xor byte2
End Sub

' This function creates a hexadecimal string to represent a number, but it
' outputs a string of a fixed number of digits.  Extra zeros are added to make
' the string the proper length.  The "&H" prefix is not put into the string.
Public Function FixedHex (ByVal hexval As Long, ByVal nDigits As Long) As String
	FixedHex = Right("00000000" & Hex(hexval), nDigits)
End Function

' *** Place the following code inside the form that has Command1 and Text1. ***

Private Sub Command1_Click()
	Dim vffi As VS_FIXEDFILEINFO  ' version info structure
	Dim buffer() As Byte          ' buffer for version info resource
	Dim pData As Long             ' pointer to version info data
	Dim nDataLen As Long          ' length of info pointed at by pData
	Dim cpl(0 To 3) As Byte       ' buffer for code page & language
	Dim cplstr As String          ' 8-digit hex string of cpl
	Dim dispstr As String         ' string used to display version information
	Dim retval As Long            ' generic return value
	
	' First, get the size of the version info resource.  If this function fails, then Text1
	' identifies a file that isn't a 32-bit executable/DLL/etc.
	nDataLen = GetFileVersionInfoSize(Text1.Text, pData)
	If nDataLen = 0 Then
		Debug.Print "Not a 32-bit executable!"
		Exit Sub
	End If
	' Make the buffer large enough to hold the version info resource.
	ReDim buffer(0 To nDataLen - 1) As Byte
	' Get the version information resource.
	retval = GetFileVersionInfo(Text1.Text, 0, nDataLen, buffer(0))
	
	' Get a pointer to a structure that holds a bunch of data.
	retval = VerQueryValue(buffer(0), "\", pData, nDataLen)
	' Copy that structure into the one we can access.
	CopyMemory vffi, ByVal pData, nDataLen
	' Display the full version number of the file.
	dispstr = Trim(Str(HIWORD(vffi.dwFileVersionMS))) & "." & _
		Trim(Str(LOWORD(vffi.dwFileVersionMS))) & "." & _
		Trim(Str(HIWORD(vffi.dwFileVersionLS))) & "." & _
		Trim(Str(LOWORD(vffi.dwFileVersionLS)))
	Debug.Print "Version Number: "; dispstr
	' Display the type of file it is (i.e., executable, DLL, etc.).
	Select Case vffi.dwFileType
	Case VFT_APP
		dispstr = "Application"
	Case VFT_DLL
		dispstr = "Dynamic Link Library (DLL)"
	Case VFT_DRV
		dispstr = "Device Driver"
	Case VFT_VXD
		dispstr = "Virtual Device Driver"
	Case Else
		dispstr = "Unknown"
	End Select
	Debug.Print "File Type: "; dispstr
	
	' Before reading any strings out of the resource, we must first determine the code page
	' and language.  The code to get this information follows.
	retval = VerQueryValue(buffer(0), "\VarFileInfo\Translation", pData, nDataLen)
	' Copy that informtion into the byte array.
	CopyMemory cpl(0), ByVal pData, 4
	' It is necessary to swap the first two bytes, as well as the last two bytes.
	SwapByte cpl(0), cpl(1)
	SwapByte cpl(2), cpl(3)
	' Convert those four bytes into a 8-digit hexadecimal string.
	cplstr = FixedHex(cpl(0), 2) & FixedHex(cpl(1), 2) & FixedHex(cpl(2), 2) & _
		FixedHex(cpl(3), 2)
	' cplstr now represents the code page and language to read strings as.
	
	' Read the copyright information from the version info resource.
	retval = VerQueryValue(buffer(0), "\StringFileInfo\" & cplstr & "\LegalCopyright", _
		pData, nDataLen)
	' Copy that data into a string for display.
	dispstr = Space(nDataLen)
	retval = lstrcpy(dispstr, pData)
	' Display the result.
	Debug.Print "Copyright Info: "; dispstr
	' Similarly, read a description of the file and display it.
	retval = VerQueryValue(buffer(0), "\StringFileInfo\" & cplstr & "\FileDescription", _
		pData, nDataLen)
	dispstr = Space(nDataLen)
	retval = lstrcpy(dispstr, pData)
	Debug.Print "File Description: "; dispstr
End Sub