System.Net.HttpUtility.UrlDecode C# (CSharp) Method

		public static string UrlDecode (string s, Encoding e)
		{
			if (null == s) 
				return null;

			if (s.IndexOf ('%') == -1 && s.IndexOf ('+') == -1)
				return s;

			if (e == null)
				e = Encoding.GetEncoding (28591);
	
			StringBuilder output = new StringBuilder ();
			long len = s.Length;
			NumberStyles hexa = NumberStyles.HexNumber;
			MemoryStream bytes = new MemoryStream ();
	
			for (int i = 0; i < len; i++) {
				if (s [i] == '%' && i + 2 < len) {
					if (s [i + 1] == 'u' && i + 5 < len) {
						if (bytes.Length > 0) {
							output.Append (GetChars (bytes, e));
							bytes.SetLength (0);
						}
						output.Append ((char) Int32.Parse (s.Substring (i + 2, 4), hexa));
						i += 5;
					} else {
						bytes.WriteByte ((byte) Int32.Parse (s.Substring (i + 1, 2), hexa));
						i += 2;
					}
					continue;
				}

				if (bytes.Length > 0) {
					output.Append (GetChars (bytes, e));
					bytes.SetLength (0);
				}

				if (s [i] == '+') {
					output.Append (' ');
				} else {
					output.Append (s [i]);
				}
	         	}
	
			if (bytes.Length > 0) {
				output.Append (GetChars (bytes, e));
			}

			bytes = null;
			return output.ToString ();
		}
	}