How to read INF file ?
INF files are just sort of INI files with the specified syntax. So to work with INF files you need to treat them as ordinary INI files. Assuming you have a INF file like this:
[Add.Code]
File.dll=File.dll
[File.dll]
File=http://www.code.com/file.dll
FileVersion=1,0,0,143
You can read the FileVersion key by using GetIniString this way:
procedure InitializeWizard;
var
Version: string;
begin
Version := GetIniString('File.dll', 'FileVersion', '', 'c:\File.inf');
if Version <> '' then
MsgBox('File version: ' + Version, mbInformation, MB_OK);
end;
Update:
1. Malformed INF file
According to your update, if the content of your INF file looks like this:
NetVersion=1.1.1.1
PatchVersion=2.0.1
ProductName=SoftwareX
then it's not a well formed INF file, but a name value pair text file saved with INF extension. Real INF files must have a valid [] section for each key value set, but this section is missing in your file.
2. GetIniString function cannot be called with empty Section parameter value
You must not call the GetIniString function with empty Section parameter value, because for the internally called GetPrivateProfileString function it means to return all section names for a given file, not value of a specified key. So for instance the following call is invalid, because the first parameter Section cannot be empty:
GetIniString('', 'KeyName', 'Default', 'c:\File.xxx');
3. How to work with a name value pair text file ?
You'll just need to work with that file as with a text file. For a key value text file handling would be ideal to use the TStringList class, or at least in Delphi. In InnoSetup unfortunately the TStringList class doesn't have published properties needed for a key value content manipulation, so you'll need to make your own key value text file parsing function. Here's the one for getting value for a given key. As the key value delimiter is supposed to be the = sign. This function returns a key value when succeed to find a AKeyName key in a given AFileName file or default ADefault value when fails:
function GetKeyValue(const AKeyName, AFileName, ADefault: string): string;
var
I: Integer;
KeyPos: Integer;
KeyFull: string;
FileLines: TArrayOfString;
begin
Result := ADefault;
if LoadStringsFromFile(AFileName, FileLines) then
begin
KeyFull := AKeyName + '=';
for I := 0 to GetArrayLength(FileLines) - 1 do
begin
FileLines[I] := TrimLeft(FileLines[I]);
KeyPos := Pos(KeyFull, FileLines[I]);
if KeyPos > 0 then
begin
Result := Copy(FileLines[I], KeyPos + Length(AKeyName) + 1, MaxInt);
Break;
end;
end;
end;
end;
To read a value of the PatchVersion key from the Sam.inf file expected in the currently selected install path you can use something like this. This script will update the label value whenever your user change the text in the directory edit box and when the directory selection page is going to be displayed:
var
// target version label must be declared globally
L2Ver2: TLabel;
procedure DirEditChange(Sender: TObject);
var
FilePath: string;
begin
// assign the expected INF file path
FilePath := AddBackslash(WizardForm.DirEdit.Text) + 'Sam.inf';
// read the PatchVersion key value, return N/A if not found
L2Ver2.Caption := GetKeyValue('PatchVersion', FilePath, 'N/A');
end;
procedure InitializeWizard;
begin
// create the target label as before
L2Ver2 := TLabel.Create(WizardForm);
...
// bind the DirEditChange method to the directory edit's OnChange event
WizardForm.DirEdit.OnChange := @DirEditChange;
end;
procedure CurPageChanged(CurPageID: Integer);
begin
// if the page has been turned to the select directory page, update the
// label caption by firing the assigned OnChange event method manually
if (CurPageID = wpSelectDir) then
DirEditChange(nil);
end;
