البحث عن كلمة في ملف

لقد كنت استعمل هذا الكود للبحث عن كلمة في ملفات , ولكن المشكلة اليوم هي ان البحث عن كلمات بالغة العربية لاتظهر يعنى البحث لايعطي اي نتيجة رغم انني استعملت بعض وحدات TntSysUtils ولكن بدون نتيجة فهل من مساعدة من فظلكم وشكرا :

هذا هو الكود :

function ScanFile(const filename: String; 
				 const forString: String; // حتى ولو إستعملت WideString فهذا لايعطي اية نتيجة  
				 caseSensitive: Boolean ): LongInt; 
{ returns position of string in file or -1, if not found } 
const 
BufferSize= $8001;  { 32K+1 bytes } 
var 
pBuf, pEnd, pScan, pPos : PWidechar; 
filesize: LongInt; 
bytesRemaining: LongInt; 
bytesToRead: Integer; 
F   : File; 
SearchFor: PWidechar; 
oldMode: Word; 
begin 
Result := -1;  { assume failure } 
if (Length( forString ) = 0) or (Length( filename ) = 0) then 
   Exit; 
SearchFor := nil; 
pBuf	  := nil; 

{ open file as binary, 1 byte recordsize } 
AssignFile( F, filename ); 
oldMode := FileMode; 
FileMode := 0;	{ read-only access } 
Reset( F, 1 ); 
FileMode := oldMode; 
try { allocate memory for buffer and pchar search string } 
   SearchFor := StrAllocW( Length( forString )+1 ); 
   StrPCopyW( SearchFor, forString ); 
  if not caseSensitive then  { convert to upper case } 

  Tnt_WideUpperCase(SearchFor ); // 
	// AnsiUpperCase( SearchFor ); 
   GetMem( pBuf, BufferSize ); 
   filesize := System.Filesize( F ); 
   bytesRemaining := filesize; 
   pPos := nil; 
   while bytesRemaining > 0 do 
   begin 
	 { calc how many bytes to read this round } 
	 if bytesRemaining >= BufferSize then 
	   bytesToRead := Pred( BufferSize ) 
	 else 
	   bytesToRead := bytesRemaining; 

	 { read a buffer full and zero-terminate the buffer } 
	 BlockRead(F, pBuf^, bytesToRead, bytesToRead); 
	 pEnd := @pBuf[ bytesToRead ]; 
	 pEnd^:= #0; 
	 { scan the buffer. Problem: buffer may contain #0 chars! So we 
	   treat it as a concatenation of zero-terminated strings. } 
	 pScan := pBuf; 
	 while pScan < pEnd do 
	 begin 
	  if not caseSensitive then { convert to upper case } 
		Tnt_WideUpperCase( pScan ); 
	   pPos := StrPosW( pScan, SearchFor );  { search for substring } 
	   if pPos <> nil then 
	   begin { Found it! } 
		 Result := FileSize - bytesRemaining + 
				   LongInt( pPos ) - LongInt( pBuf ); 
		 Break; 
	   end; 
	   pScan := StrEndW( pScan ); 
	   Inc( pScan ); 
	 end; 
	 if pPos <> nil then 
	   Break; 
	 bytesRemaining := bytesRemaining - bytesToRead; 
	 if bytesRemaining > 0 then 
	 begin 
	 { no luck in this buffers load. We need to handle the case of 
	   the search string spanning two chunks of file now. We simply 
	   go back a bit in the file and read from there, thus inspecting 
	   some characters twice 
	 } 
	   Seek( F, FilePos(F)-Length( forString )); 
	   bytesRemaining := bytesRemaining + Length( forString ); 
	 end; 
   end; { While } 
finally 
   CloseFile( F ); 
   If SearchFor <> nil then 
	 StrDisposeW( SearchFor ); 
   If pBuf <> nil then 
	 FreeMem( pBuf, BufferSize ); 
end; 
end; { ScanFile } 
procedure GetFileList( FileList: TStringList; inDir, Extension : String ); 
procedure ProcessSearchRec( aSearchRec : TSearchRecW ); 
var 
  sDate: String; 
begin 
   if ( aSearchRec.Attr and faDirectory ) <> 0 then 
   begin 
	 if ( aSearchRec.Name <> '.' ) and 
		( aSearchRec.Name <> '..' ) then 
	 begin 
	   GetFileList( FileList, Extension, InDir + '\' + aSearchRec.Name ); 
	 end; 
   end 
   else 
   begin 
	 sDate := DateTimeToStr(FileDateToDateTime(aSearchRec.Time)); 
	 FileList.Add(inDir + '\' + aSearchRec.Name); 

   end; 

end; 

var CurDir : String; 
aSearchRec : TSearchRecW; 
begin 
CurDir := inDir + '\*.' + Extension; 
if WideFindFirst( CurDir, faAnyFile, aSearchRec ) = 0 then 
begin 
   ProcessSearchRec( aSearchRec ); 
   while WideFindNext( aSearchRec ) = 0 do 
	 ProcessSearchRec( aSearchRec ); 
end; 
WideFindClose(aSearchRec); 

end; 



procedure TForm1.GetHTMLFileList(Directory, SearchString: WideString; 
  CaseSens: Boolean); 
var 
FL: TStringList; 
begin 
FL := TStringList.Create; 
FL.Sorted := True; 
GetFileList(FL, Directory, 'HTM*'); 
ProcessHTMLFIles(FL, SearchString, CaseSens); 
FL.Free; 
end; 


procedure TForm1.ProcessHTMLFiles(FileList: TStringList; 
  SearchString: WideString; CaseSens: Boolean); 
var 
i: Integer; 
begin 
for i := 0 to Pred(FileList.Count) do 
begin 
   if ScanFile(FileList.Strings, SearchString, CaseSens) > 0 then 
   begin 
	 // The result was found 
	 Memo1.Lines.Add(FileList.Strings); // هنا استعمل  TntMemo لإظهار إسم الملفات التي تحتوي على الكلمة المراد البحث عنها
   end; 
end; 
end;