Creating an Uri in .NET automatically urldecodes all parameters from passed string

Question

Suppose I want to create an Uri object from the following string:

string url = @"http://someserver.com?param1=1&url=http%3a%2f%2fwww.otherserver.com";
Uri uri = new Uri(url, UriKind.Absolute);

Expected result would be:

http://someserver.com?param1=1&url=http%3a%2f%2fwww.otherserver.com 

Obtained:

http://someserver.com/?param1=1&url=http://www.otherserver.com

The same behavior is noticed in many related methods that allow Uri creation: Uri.TryCreate, UriBuilder.Uri, etc.

How would I get an Uri that preserve initial encoded parameter?

Answer 1

In .NET4 you can disable Uri compaction for certain scheme via a configuration:

<configuration>
  <uri>
    <schemeSettings>
      <add name="http" genericUriParserOptions="DontUnescapePathDotsAndSlashes"/>
    </schemeSettings>
  </uri>
</configuration>

Note that there are security implications related to disabling of the default behaviour.

Answer 2

How did you "obtain" the URL? If I hover my mouse over it in Visual Studio, it indeed shows the decoded URL.

But whenever I access it through the AbsoluteUri property, it shows the encoded URL.

Answer 3

This behavior is documented:

As part of canonicalization in the constructor for some schemes, escaped representations are compacted. The schemes for which URI will compact escaped sequences include the following: file, http, https, net.pipe, and net.tcp. For all other schemes, escaped sequences are not compacted. For example: if you percent encode the two dots ".." as "%2E%2E" then the URI constructor will compact this sequence for some schemes. For example, the following code sample shows a URI constructor for the http scheme.

So one workaround might be temporarily using a custom scheme (e.g. leavemealone://) to construct the URL objects (possibly through UriBuilder?).