function BinStringToLongInt(BinString : string) : longint; 
var 
  i : integer; 
  Num : longint; 
begin 
  Num := 0; 
  for i := 1 to length(BinString) do 
   if BinString[i] = '1' then 
     Num := (Num shl 1) + 1 else 
     Num := (Num shl 1); 
  Result := Num; 
end; 
 
procedure TForm1.Button1Click(Sender: TObject); 
begin 
 Memo1.Lines.Add(IntToStr(BinStringToLongInt('11111111'))); 
end;