How can I use GetVolumeInformation in Inno Setup?

Question

I need to get the volume serial number for a drive letter during an installation created with Inno Setup. I know that DLL functions can be imported into Inno, but I'm fairly new to it and having some problems getting it to work. I know that the GetVolumeInformation function in kernel32 can do what I need. Could someone show me how to import and use that functionality in an Inno script to retrieve the volume serial number?

Thanks!

Answer 1

Inno-Setup code::

[Code]
function GetVolumeInformation(
  lpRootPathName: PChar;
  lpVolumeNameBuffer: PChar;
  nVolumeNameSize: DWORD;
  var lpVolumeSerialNumber: DWORD;
  var lpMaximumComponentLength: DWORD;
  var lpFileSystemFlags: DWORD;
  lpFileSystemNameBuffer: PChar;
  nFileSystemNameSize: DWORD
  ): BOOL;
  external 'GetVolumeInformationA@kernel32.dll stdcall';


function LoWord(dw: DWORD): WORD;
begin
  Result := WORD(dw);
end;

function HiWord(dw: DWORD): WORD;
begin
  Result := WORD((dw shr 16) and $FFFF);
end;

function WordToHex(w: WORD): string;
begin
  Result := Format('%.4x', [w]);
end;

function FindVolumeSerial(const Drive: string): string;
var
  FileSystemFlags: DWORD;
  VolumeSerialNumber: DWORD;
  MaximumComponentLength: DWORD;
begin
  Result := '';
  // Note on passing PChars using RemObjects Pascal Script:
  // '' pass a nil PChar  
  // #0 pass an empty PChar    
  if GetVolumeInformation(
    PChar(Drive), 
    '', // nil
    0,
    VolumeSerialNumber,
    MaximumComponentLength,
    FileSystemFlags,
    '', // nil
    0)
  then
    Result := WordToHex(HiWord(VolumeSerialNumber)) + '-' + WordToHex(LoWord(VolumeSerialNumber));
end;

function InitializeSetup(): Boolean;
begin
  MsgBox(FindVolumeSerial('c:\'), mbInformation, mb_Ok);
end;

---

Tested with Inno-setup version 5.2.3
In Unicode versions of Inno-Setup replace PChar with PAnsiChar

Answer 2

Since the InnoSetup doesn't support pointers you will have to create the external library for the call of the GetVolumeInformation function. The following code samples should work for all combinations of the Delphi and InnoSetup (from the Unicode support point of view).

Here's the Delphi library code:

library VolumeInformation;

uses
  Types, Classes, SysUtils, Windows;

var
  SerialNumber: AnsiString;

function GetVolumeSerial(Drive: PAnsiChar): PAnsiChar; stdcall;
var
  FileSystemFlags: DWORD;
  VolumeSerialNumber: DWORD;
  MaximumComponentLength: DWORD;
begin
  SerialNumber := '';
  GetVolumeInformationA(Drive, nil, 0, @VolumeSerialNumber,
    MaximumComponentLength, FileSystemFlags, nil, 0);
  SerialNumber := IntToHex(HiWord(VolumeSerialNumber), 4) + ' - ' +
    IntToHex(LoWord(VolumeSerialNumber), 4);
  Result := PAnsiChar(SerialNumber);
end;

exports
  GetVolumeSerial;

end.

And here's the InnoSetup code:

[Files]
Source: "VolumeInformation.dll"; Flags: dontcopy

[Code]

function GetVolumeSerial(Drive: PAnsiChar): PAnsiChar;
  external 'GetVolumeSerial@files:VolumeInformation.dll stdcall setuponly';

procedure ButtonOnClick(Sender: TObject);
var
  S: string;
begin
  S := GetVolumeSerial('c:\');
  MsgBox(S, mbInformation, mb_Ok);
end;