UWP POST request like GET - post

Question

I need to send POST request from my UWP app.
I read about it here.
I use one shared HttpClient.
private Windows.Web.Http.HttpClient httpClient;
Initialization:
httpClient = new Windows.Web.Http.HttpClient();
var headers = httpClient.DefaultRequestHeaders;
string header = "Chrome/64.0.3282.140";
if (!headers.UserAgent.TryParseAdd(header))
{
throw new Exception("Invalid header value: " + header);
}
I use this object for all request
But when I use it for POST request, it works like GET request or POST, but without parameters
Uri requestUri = new Uri("http://some_websit.ru");
Dictionary<string, string> pairs = new Dictionary<string, string>();
pairs.Add("par1", "val1");
pairs.Add("par2", "val2");
HttpFormUrlEncodedContent formContent = new HttpFormUrlEncodedContent(pairs)
var result = await httpClient.PostAsync(requestUri, formContent);
string resultContent = await result.Content.ReadAsStringAsync();
It ignore parameters which I give.
I tried to send POST request here http://seriyps.ru/postget/ and it works.

Answer 1

There is nothing wrong with your code, I have tested it locally with the same code, only a different URL, and the POST request is sent properly along with the passed in parameters:
I recommend you to install Telerik Fiddler 4 to see the network traffic and confirm that the parameters are indeed sent. I have used http://example.com just as a sample URL here. I would suspect the problem is rather on the side of the server than your app or that the server expect different parameters than what is being sent.