String和byte[]的转换 (C#)

string类型转成byte[]：



 



byte[] byteArray = System.Text.Encoding.Default.GetBytes ( str );

反过来，byte[]转成string：



 



string str = System.Text.Encoding.Default.GetString ( byteArray );



其它编码方式的，如System.Text.UTF8Encoding，System.Text.UnicodeEncoding class等；例如：



 



 



string类型转成ASCII byte[]：（"01" 转成 byte[] = new byte[]{ 0x30, 0x31}）



 



byte[] byteArray = System.Text.Encoding.ASCII.GetBytes ( str );

ASCII byte[] 转成string：（byte[] = new byte[]{ 0x30, 0x31} 转成 "01"）



 



string str = System.Text.Encoding.ASCII.GetString ( byteArray );

 



有时候还有这样一些需求：



byte[] 转成原16进制格式的string，例如0xae00cf, 转换成 "ae00cf"；new byte[]{ 0x30, 0x31}转成"3031":



 



        public static string ToHexString ( byte[] bytes ) // 0xae00cf => "AE00CF "

        {

            string hexString = string.Empty;

            if ( bytes != null )

            {

                StringBuilder strB = new StringBuilder ();



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

                {

                    strB.Append ( bytes[i].ToString ( "X2" ) );

                }

                hexString = strB.ToString ();

            }

            return hexString;

        }



反过来，16进制格式的string 转成byte[]，例如, "ae00cf"转换成0xae00cf，长度缩减一半；"3031" 转成new byte[]{ 0x30, 0x31}:



 



        public static byte[] GetBytes(string hexString, out int discarded)

        {

            discarded = 0;

            string newString = "";

            char c;

            // remove all none A-F, 0-9, characters

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

            {

                c = hexString[i];

                if (IsHexDigit(c))

                    newString += c;

                else

                    discarded++;

            }

            // if odd number of characters, discard last character

            if (newString.Length % 2 != 0)

            {

                discarded++;

                newString = newString.Substring(0, newString.Length-1);

            }



            int byteLength = newString.Length / 2;

            byte[] bytes = new byte[byteLength];

            string hex;

            int j = 0;

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

            {

                hex = new String(new Char[] {newString[j], newString[j+1]});

                bytes[i] = HexToByte(hex);

                j = j+2;

            }

            return bytes;

        }