c#模拟js escape方法

public static string Escape(string s)

        {

            StringBuilder sb = new StringBuilder();

            byte[] ba = System.Text.Encoding.Unicode.GetBytes(s);

            for (int i = 0; i < ba.Length; i += 2)

            {

                if (ba[i + 1] == 0)

                {

                    //数字,大小写字母,以及"+-*/._"不变

                    if (

                          (ba[i] >= 48 && ba[i] <= 57)

                        || (ba[i] >= 64 && ba[i] <= 90)

                        || (ba[i] >= 97 && ba[i] <= 122)

                        || (ba[i] == 42 || ba[i] == 43 || ba[i] == 45 || ba[i] == 46 || ba[i] == 47 || ba[i] == 95)

                        )//保持不变

                    {

                        sb.Append(Encoding.Unicode.GetString(ba, i, 2));



                    }

                    else//%xx形式

                    {

                        sb.Append("%");

                        sb.Append(ba[i].ToString("X2"));

                    }

                }

                else

                {

                    sb.Append("%u");

                    sb.Append(ba[i + 1].ToString("X2"));

                    sb.Append(ba[i].ToString("X2"));

                }

            }

            return sb.ToString();

        }