从C＃到Flask REST API的HTTP Post请求不会附加任何参数？

Question

I have been attempting to do a simple POST request to a basic Flask API, and no matter what I try it simply will do http://localhost:5000/ rather than the http://localhost/?test_key=test_value that I want it to do. C# is not my strongest language, but I have tried a bunch of different methods that I found online. I don't think it has to do with my method being bad at this point, I more so think that I'm missing a major piece entirely.

Here is the most recent attempt I tried (keep in mind this is a snippet of a far larger project, but it doesn't involve any other pieces of it):

    class DisputeResponse
    {
        public int id;
        public string res;
        public string test_key;
    }

    [HttpPost]
    public async Task<JsonResult> TestResponse(int id, string res)
    {
        HttpClient client = new HttpClient();

        client.BaseAddress = new Uri("http://localhost:5000/");
        client.DefaultRequestHeaders.Accept.Clear();
        client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

        try
        {
            var dispRes = new DisputeResponse();
            dispRes.test_key = "test_value";

            var result = await client.PostAsync("http://localhost:5000/",
                new StringContent(JsonConvert.SerializeObject(dispRes), Encoding.UTF8, "application/json"
                ));

            result.EnsureSuccessStatusCode();
        }
        catch (Exception e)
        {
            System.Diagnostics.Trace.TraceInformation(e.Message);
        }


        return null;
    }

Here is the output when I use Postman (works perfectly):
127.0.0.1 - - [15/Apr/2019 16:26:28] "POST /?test_key=test_value HTTP/1.1" 200 -

And here is when I try to use C# code:
127.0.0.1 - - [15/Apr/2019 16:36:54] "POST / HTTP/1.1" 500 -

EDIT: Sorry I had some extraneous lines that I removed.

Answer 1

The HTTPClient is putting the parameters inside the body of the request. If you would like to add it to the URI you can do so by modifying the URI string. If you are not posting anything to the body, I would modify the FLASK API to receive a GET instead of a POST.

Typically I would only use query string parameters in the URI string for HTTPGet requests, even though there is no rule stopping you from doing this with a HTTPPost. Additionally, I would only include my parameters for an HTTPPost request within the body. Again, no rule for this but just what I do.

Here are a few examples to help you along with the HTTPClient post async method:

https://csharp.hotexamples.com/examples/-/HttpClient/PostAsync/php-httpclient-postasync-method-examples.html