How to convert IDN to ASCII?

Question

What is the best way to convert an internationalized domain name to its ASCII-form?

I want to convert Bücher.ch into xn--

Answer 1

Have a look at the GNU IDN Library - Libidn. The introduction says that C# libraries are available.

Answer 2

using System.Globalization;
...
IdnMapping idn = new IdnMapping();
MessageBox.Show(idn.GetAscii("www.kraków.pl"));

Answer 3

To Get the other way around from xn--bcher-kva.ch domain to Bücher.ch

using System.Globalization;
...
IdnMapping idn = new IdnMapping();
MessageBox.Show(idn.GetUnicode("xn--bcher-kva.ch"));

You will get www.kraków.pl as result. Because i came here to look for this :) hope it is helpful for others as well :)

MSDN