string类型转成byte[]：
byte[] byteArray = System.Text.Encoding.Default.GetBytes ( str );
byte[]转成string：
string str = System.Text.Encoding.Default.GetString ( byteArray );
string类型转成ASCII byte[]：
（"01" 转成 byte[] = new byte[]{ 0x30,0x31}）
byte[] byteArray = System.Text.Encoding.ASCII.GetBytes ( str );
ASCIIbyte[]转成string：
（byte[] = new byte[]{ 0x30, 0x31} 转成"01"）
string str = System.Text.Encoding.ASCII.GetString ( byteArray );
byte[]转16进制格式string：
new byte[]{ 0x30, 0x31}转成"3031":
publicstaticstring 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;
}
16进制格式string 转byte[]：
publicstaticbyte[] GetBytes(string hexString, outint discarded)
{
discarded = 0;
string newString = "";
char c;// remove all none A-F, 0-9, charactersfor (int i=0; i<hexString.Length; i++)
{
c = hexString[i];if (IsHexDigit(c))
newString += c;
else
discarded++;
}// if odd number of characters, discard last characterif (newString.Length % 2 != 0){ discarded++;
newString = newString.Substring(0, newString.Length-1); }
int byteLength = newString.Length / 2;byte[] bytes = newbyte[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;
}
来源：https://www.cnblogs.com/Maxq/p/5953682.html