/// <summary>
        /// 字串轉Unicode 直接Byte的方式，單位元組操作
        /// </summary>
        /// <param name="source">源字串</param>
        /// <returns>Unicode編碼後的字串</returns>
        public static string StringToUnicode(string source)
        {
            var bytes = Encoding.Unicode.GetBytes(source);
            
 
var stringBuilder = new StringBuilder();
            for (var i = 0; i < bytes.Length; i += 2)
            {     
                stringBuilder.AppendFormat("\\u{0:x2}{1:x2}", bytes[i + 1], bytes[i]);
            }
            return stringBuilder.ToString();
        }

        /// <summary>  
        ///
 
 字串轉為UniCode碼字串    通過Char的方式，一個Char為兩個位元組
        /// </summary>  
        /// <param name="s"></param>  
        /// <returns></returns>  
        public static string StringToUnicode(string s)
        {
            char[] charbuffers = s.ToCharArray();
            byte[] buffer;
            StringBuilder sb 
 
= new StringBuilder();
            for (int i = 0; i < charbuffers.Length; i++)
            {
                buffer = System.Text.Encoding.Unicode.GetBytes(charbuffers[i].ToString());
                sb.Append(String.Format("\\u{0:X2}{1:X2}", buffer[1], buffer[0]));
            }
            return sb.ToString();
        }

        /// <summary>  
        /// Unicode字串轉為正常字串  例如：1的Unicode為 \u0031
        /// </summary>  
        /// <param name="srcText"></param>  
        /// <returns></returns>  
        public static string UnicodeToString(string srcText)
        {
            string dst = "";
            string src = srcText;
            int len = srcText.Length / 6;
            for (int i = 0; i <= len - 1; i++)
            {
                string str = "";
                str = src.Substring(0, 6).Substring(2);
                src = src.Substring(6);
                byte[] bytes = new byte[2];
                bytes[1] = byte.Parse(int.Parse(str.Substring(0, 2), System.Globalization.NumberStyles.HexNumber).ToString());
                bytes[0] = byte.Parse(int.Parse(str.Substring(2, 2), System.Globalization.NumberStyles.HexNumber).ToString());
                dst += Encoding.Unicode.GetString(bytes);
            }
            return dst;
        }

測試環境：https://try.dot.net/

轉自 https://blog.csdn.net/u011511086/article/details/72865006/