c# - HttpUtility.ParseQueryString() always encodes special characters to unicode

Question

When using HttpUtility from System.Web, I find that everytime I call the method .ParseQueryString I am having special characters encode to their unicode equivalent representations. I have tried with many different encoding types, and all seem to produce the same result. An example of my code is here:

string text = "ich m?chte diese Bild für andere freigeben"
var urlBuilder = new UriBuilder(url);
var query = HttpUtility.ParseQueryString(urlBuilder.Query, Encoding.UTF8);
query["text"] = text;    
urlBuilder.Query = query.ToString();
string finalUrl = urlBuilder.ToString();

And the string in finalUrl that I would recieve from this would be:

text=ich+m%u00f6chte+diese+Bild+f%u00fcr+andere+freigeben

I have tried using Encoding.UTF8,Encoding.ASCII and Encoding.Default and they all produce the same result. What can I do to reach my desired format of UrlEncoding:

text=ich%20m%C3%B6chte%20diese%20Bild%20f%C3%BCr%20andere%20freigeben

As always, Thanks in advance for the help/advice!

Answer 1

The problem is in:

urlBuilder.Query = query.ToString();

HttpUtility.ParseQueryString returns a NameValueCollection but is actually an internal class called HttpValueCollection. This class has an override of the ToString() method. It generates an encoded query string but for its URL encoding it uses HttpUtility.UrlEncodeUnicode (tinyurl.com/HttpValue). This results in the %uXXXX values.

If you need a different type of URL encoding you might want to avoid HttpUtility.ParseQueryString or decode the result of ToString() and encode it afterwards:

urlBuilder.Query = Uri.EscapeUriString(HttpUtility.UrlDecode(query.ToString()));