Ionic: My http.post to WebApi RestFull doesn't work

Issue

I'm developing an app with Ionic Framework and I'm changing some of the information with my web service API RestFull. When I connect with a GET method it works, but when I try to connect with a POST method it doesn't work.

This is the code of Ionic:

import { HttpClient ] from '@angular/common/http';

constructor(private http: HttpClient ...)

And this is the function (I am returning a promise):

var user = {"nom" : "whatever", "password" : "whatever2"};
var options =  { headers: {'Content-Type': 'application/json; charset=utf-8;'}};

return this.http.post(myLink, user, options).toPromise();

In Web Service, the code is (C#):

[Route("AuthFullUser")]
[HttpPost]
public HttpResponseMessage login([FromBody]User user){
var u = UserRepository.login(user.nom.ToString(), user.password.ToString());
HttpResponseMessage response = Request.CreateResponse(HttpStatusCode.OK, u);

return response;
}

If I try to enter from Ionic doesn't work, but with PostMan (an app) it works.

On the other hand, if I put [HttpOptions] above the [Route("AuthFullUser")] I am able to access the web service but the parameters are NULL.

I tried to make a request with $.ajax{} or $.post{} but neither worked.

I tried to add on my headers:

"Acces-Control-Allow-Origin" : "*",
"Acces-Control-Allow-Credentials" : "true",
"Acces-Control-Allow-Methods" : "GET, POST, PUT, DELETE, OPTIONS",
"Acces-Control-Allow-Headers" : "Content-Type"

But neither worked.

I have been struggling for weeks on this. Any help would be greatly appreciated.

Solution

If someone is having the same trouble I found the solution.

It was all from the Web Service and his headers. You only need to allow all the headers, it's all on the documentation.

If someone have a question, they can put it here and i will try to give my best answer.

Answered By - Eric FD