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?

Expected result of doing what? If I try your code in a Console Application `Console.WriteLine(uri.AbsoluteUri);` returns the encoded url — Paolo Falabella, Sep 05 '11 at 12:16
For other searching regarding this. It is actually the ToString() method that decodes the string. .OriginalString or .AbsoluteUri will return the encoded string. For a relative url, use .PathAndQuery — jishi, Feb 17 '14 at 15:01

score 6 · Answer 1 · edited Nov 11 '12 at 00:11

6

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.

edited Nov 11 '12 at 00:11

John Gietzen

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answered Jun 05 '12 at 02:39

Pencho Ilchev

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score 4 · Answer 2 · answered Sep 05 '11 at 12:12

4

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.

answered Sep 05 '11 at 12:12

CodeCaster

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Well I'm describing observed behaviour. It's an asp.net mvc app but it does not matter. – Eugeniu Torica Sep 05 '11 at 13:10
I didn't ask what, I asked how. – CodeCaster Sep 05 '11 at 13:32
ooops sorry. I formed using asp.net mvc routing but I need to make some tweeks to it. – Eugeniu Torica Sep 05 '11 at 13:35
I was responding to your "obtained". It only prints like that when you cast it to a string. The `AbsoluteUri` property gives you what you want. – CodeCaster Sep 05 '11 at 13:42

score 3 · Accepted Answer · answered Sep 05 '11 at 12:16

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?).

Interestingly, I discovered the compaction to also occur with `rtsp://`. The documentation is vague about which are included (saying "some" schemes are left uncompacted, and ones which are compacted "include" these). — Joseph, Aug 22 '19 at 00:08

score 0 · Answer 4 · answered Jun 01 '20 at 09:24

I recommend using the library Flurl. It allows a fluent and correct build and analysis of URIs. See their examples. https://flurl.dev/docs/fluent-url/

It is available as NuGet package. You don't need the HTTP-Stuff

    using Flurl;

    var url = "http://www.some-api.com"
    .AppendPathSegment("endpoint")
    .SetQueryParams(new {
        api_key = ConfigurationManager.AppSettings["SomeApiKey"],
        max_results = 20,
        q = "Don't worry, I'll get encoded!"
    })
    .SetFragment("after-hash");

score 0 · Answer 5 · answered Sep 05 '11 at 13:26

0

In my case I solved it by returning ToString() method of UriBuilder class instead of using Uri property of the same class.

answered Sep 05 '11 at 13:26

Eugeniu Torica

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

5 Answers5

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