Angular 2, typescript post to API model is null - api

Question

I have downloaded the following project: http://www.asp.net/web-api/overview/security/individual-accounts-in-web-api. I run it on VS2015 and IIS express. The project is fine but i want to call the API with Angular 2.
So i have setup my project in Visual Studio Code and made a project in Angular 2 and TypeScript. When I try to post to the API method named Register, the values are null ?
My Visual Studio Code service(Angular2)
import { Injectable } from 'angular2/core';
import { Account } from '../account/Account';
import { RegisterBindingModel } from '../account/RegisterBindingModel';
import {Http, Response, Headers, RequestOptions} from 'angular2/http';
import {Observable} from 'rxjs/Observable';
import 'rxjs/Rx';
#Injectable()
export class AccountService {
constructor(private _http: Http) {
}
createAccount(account: Account): Observable<string> {
console.log('accountService.createAccount');
let body = JSON.stringify({ account });
console.log('T1' + body);
let headers = new Headers({ 'Content-Type': 'application/json' });
let options = new RequestOptions({ headers: headers });
return this._http.post('https://localhost:44305/api/Account/Register', body, options)
.map(this.extractData)
.catch(this.handleError);
Browser error and post values:
Server API errors:
Error2_In_API_Method
I can do a GET operation, but all my POST operations are NULL ?

Answer 1

I found the following, not very effektiv, but working solution, where I map the account class objects to a new object. Then I stringify the new object and post it:
createAccount(account: Account): Observable<string> {
var obj = { Email: account.Email, Password: account.Password, ConfirmPassword: account.ConfirmPassword };
let headers = new Headers({ 'Content-Type': 'application/json' });
let options = new RequestOptions({ headers: headers });
let body = JSON.stringify(obj);
return this._http.post('https://localhost:44305/api/Account/Register', body, options)
.map(this.extractData)
.catch(this.handleError);
}
For the first error I had on the API, i solved it by changing the following:
Request.GetOwinContext().GetUserManager<ApplicationUserManager>();
To
HttpContext.Current.GetOwinContext().GetUserManager<ApplicationUserManager>();
And then I could get the GetOwinContext() from the POST