如何在C＃中的字符串后面添加控制字符？

Question

I see similar answers here but none are what I need.

I am trying to build a socket acknowledgement where the string message starts with a 0B control character and has both a hex 1C and a hex 0D at the end of the transaction.

StringBuilder sb = new StringBuilder();
char b = '\u000b'; 
char c = '\u001c';
char d = '\u000d';
sb.Append(b);
sb.AppendLine(ackMessage);
sb.Append("MSA|AA|" + controlID);
sb.Append(c);
sb.Append(d);
string myMessage = sb.ToString();

The receiver of the message is not seeing the control characters at the beginning and end of the block, and I'm not sure where I am coding wrong. Any help would be greatly appreciated. I don't know how to copy the code here in proper format so please forgive the formatting of this question ;)

Thanks.

Greg

Answer 1

Strings and chars in .NET are Unicode. Is your consumer expecting Unicode? Maybe you need to create / pass a ASCII byte array instead?

    byte[] unicodeBytes = Encoding.Unicode.GetBytes(ackMessage);
    var asciiBytes = new List<byte>(ackMessage.Length + 3);
    asciiBytes.Add(0x0b);
    asciiBytes.AddRange(Encoding.Convert(Encoding.Unicode, Encoding.ASCII, unicodeBytes));
    asciiBytes.AddRange(new byte[] { 0x1c, 0x0d });