下面代码是c#代码，哪位仁兄能帮忙转成flax代码（主要是解密代码的转化）。求,该如何解决

下面代码是c#代码，哪位仁兄能帮忙转成flax代码（主要是解密代码的转化）。急求
//加密代码  
public static string EncrypKey(string Src, string Key)
  {
  //int idx;
  //Src = GB2312ToUTF8(Src);
  if (Src == "")
  {
  return "";
  }
  int KeyLen;
  int KeyPos;
  int offset;
  string Dest;
  int SrcPos;
  int SrcAsc;
  int TmpSrcAsc;
  //int Range;
  KeyLen = Key.Length;
  if (KeyLen == 0)
  Key = "Think Space";
  KeyPos = -1;
  SrcPos = 0;
  SrcAsc = 0;
  //Range=256;
  Random r = new Random(unchecked((int)DateTime.Now.Ticks));
  offset = r.Next(0, 256);
  Dest = offset.ToString("X02");
  for (SrcPos = 0; SrcPos < Src.Length; SrcPos++)
  {
  SrcAsc = ((int)Src[SrcPos] + offset) % 255;
  if (KeyPos < KeyLen - 1)
  KeyPos = KeyPos + 1;
  else
  KeyPos = 0;
  SrcAsc = SrcAsc ^ (int)Key[KeyPos];
  Dest = Dest + SrcAsc.ToString("X02");
  offset = SrcAsc;
  }
  return Dest;
  }

  //解密函数
  public static string UncrypKey(string Src, string Key)
  {
  //int idx;
  int KeyLen;
  int KeyPos;
  int offset;
  string Dest = "";
  int SrcPos;
  int SrcAsc;
  int TmpSrcAsc;
  //int Range; 
  if (Src == "")
  {
  return "";
  }

  KeyLen = Key.Length;
  if (KeyLen == 0) Key = "Think Space";
  KeyPos = -1;
  SrcPos = 0;
  SrcAsc = 0;
  //Range=256;
  offset = Convert.ToInt32(Src.Substring(0, 2), 16);
  SrcPos = 2;
  do
  {
  SrcAsc = Convert.ToInt32(Src.Substring(SrcPos, 2), 16);
  if (KeyPos < KeyLen - 1)
  KeyPos = KeyPos + 1;
  else
  KeyPos = 0;
  TmpSrcAsc = SrcAsc ^ (int)Key[KeyPos];
  if (TmpSrcAsc <= offset)
  TmpSrcAsc = 255 + TmpSrcAsc - offset;
  else
  TmpSrcAsc = TmpSrcAsc - offset;
  Dest = Dest + (char)TmpSrcAsc;
  offset = SrcAsc;
  SrcPos = SrcPos + 2;

  } while (SrcPos < Src.Length - 1);
  return Dest;
  }

------解决方案--------------------
public static function UncrypKey(Src:String,Key:String):String
{
//int idx;
var KeyLen:int;
var KeyPos:int;
var offset:int;
var Dest:String = "";
var SrcPos:int;
var SrcAsc:int;
var TmpSrcAsc:int;
//int Range; 
if (Src == "")
{
return "";