Is there a way to pass properly a string containing a “?” to .net core web api?

Question

I have the following action that gets a Question model from my API given the Question title from an autocomplete input. The action is working fine with titles that do not contain a question mark (Ex. How old are you). But if I give a title containing a question mark (Ex. How old are you?) the model is not returned as the question mark is being removed in the process.

I tried HttpUtility.UrlDecode() method but with no luck .

Below you can find my requests

[HttpGet]
public async Task<IActionResult> GetQuestionAsync(string question) {
    Questions q = new Questions();
    HttpClient client = _api.Initial();
    HttpResponseMessage res = await client.GetAsync("api/Search/" + question);
    if (res.IsSuccessStatusCode) {
        var result = res.Content.ReadAsStringAsync().Result;
        q = JsonConvert.DeserializeObject<Questions>(result);
    }
    return View(q);
}

[Produces("application/json")]
[HttpGet]
[Route("{keyword}")]
public async Task<IActionResult> GetByString([FromRoute(Name = "keyword")] string keyword) {
    if (!ModelState.IsValid) {
        return BadRequest(ModelState);
    }
    var question = await _context.Questions
        .SingleOrDefaultAsync(m => m.Question == HttpUtility
            .UrlDecode(keyword.ToString()));

    if (question == null) {
        return NotFound();
    }
    return Ok(question);
}

I expect to be able to get questions including ? from my API. Is there a way to achieve this?

Note that in Swagger, the API Get request is working fine!

Answer 1

You need to use HttpUtility.UrlEncode - not Decode . You want to change the ? into an encoded character before sending it in the URL. HttpUtility.UrlDecode does the opposite.