C#バイトbyteタイプ読み込みと書き込み

// 

            //File.Create(@"D:\a.txt");

            //Console.WriteLine(" ");



            //// 

            //File.Delete(@"D:\a.txt");

            //Console.WriteLine(" ");



            //string st1 = " ， ";

            //byte[] bt = Encoding.Default.GetBytes(st1);

            //File.WriteAllBytes(@"D:\a.txt", bt);



            //byte[] str=File.ReadAllBytes(@"D:\a.txt");



            //string strr = Encoding.GetEncoding("utf-8").GetString(str);



           // File.WriteAllLines(@"D:\a.txt", new string[] { "123123", " ", "asd3dasd2222" });

            //Console.WriteLine(strr);