c# - Encode header value using WebClient.Headers.Add() -

i using http headers send string contains unicode characters (such ñ) custom http server.

when add string header:

webclient.headers.add("custom-data", "señor"); 

it interpreted server as:

se�or 

obviously need encode value differently, unsure encoding use.

how should encode http header preserve extended/special characters?

• pornel's answer related question confusing.
• unanswered, related: c# webclient non-english request header value encoding

as @jordan suggested, representing string base64 (with utf8 encoding) worked well:

on client side:

webclient.headers.add("custom-data",     convert.tobase64string(encoding.utf8.getbytes("señor"))); 

and on server:

string customdata = encoding.utf8.getstring(convert.frombase64string(customheader.value));