HttpClient encoding of URL parameters containing a /

Question

I'm using HttpClient (Dot Net 5) and I'm trying to get an entity from a DotNetCore web service by specifying it's id in the URL.

• It works if the id does not contain any characters that need encoding.
• It fails (HTTP 404) if the id contains a slash (/).
  • Web service diagnostics confirm that the request does not reach the method.

Other clients such as Postman or Swagger work fine.

Example of failing:

string id = "Person/65-C";
var httpResponse = await httpClient.GetAsync(string.Format("/persons/{0}", System.Web.HttpUtility.UrlEncode(id)));

Answer 1

I ran into the same problem. Spent ours to find a solution without any luck. I ended up changing my route and converting my route parameter to QueryString parameter instead. May not be an ideal solution for every scenario, but worked in my case.

Changed the route from

$"api/album/{HttpUtility.UrlEncode("a/b")}"

to

$"api/album/url=a/b"

And in controller

[HttpGet]
public TestModel Get([FromQuery] string url)
{
}

Answer 2

I suggest you should use [HttpGet("persons/{**value}")] attribute in your server api.

My test sample code.

[HttpGet("persons/{**value}")]
public string test(string value)
{
    return "userid: = " + value;
}