How can decrypte SHA256 ?

Hi ,

I am using follwoing process to Encrypt the certain text .How can i decrypt the result.

public static string GetSHA256(string text)
  {
      UnicodeEncoding ue = new UnicodeEncoding();
      byte[] hashValue;
      //byte[] message = ue.GetBytes("NYRR" + text + "RRYN");
      byte[] message = ue.GetBytes(text.Length * 2 + text + text.Length * 2);

      SHA256Managed hashString = new SHA256Managed();
      string hex = "";

      hashValue = hashString.ComputeHash(message);
      foreach (byte x in hashValue)
      {
          hex += String.Format("{0:x2}", x);
      }
      return hex;
  }

public static string GetSHA256(string text)
  {
      UnicodeEncoding ue = new UnicodeEncoding();
      byte[] hashValue;
      //byte[] message = ue.GetBytes("NYRR" + text + "RRYN");
      byte[] message = ue.GetBytes(text.Length * 2 + text + text.Length * 2);

      SHA256Managed hashString = new SHA256Managed();
      string hex = "";

      hashValue = hashString.ComputeHash(message);
      foreach (byte x in hashValue)
      {
          hex += String.Format("{0:x2}", x);
      }
      return hex;
  }