Angular 2 Token: Response for preflight has invalid HTTP status code 400

Question

I have an Angular2/TypeScript application running i Visual Studio Code.

An API running in VS 2015. This is the API project: http://www.asp.net/web-api/overview/security/

Answer 1

Another native solution is by using HttpParams class and it's toString() method:

 let headers = new Headers({ 'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8' });
    let options = { headers, observe: 'response' };

   const body = new HttpParams()
      .set('grant_type', 'password')
      .set('username', accountInfo.username)
      .set('password', accountInfo.password);

    return this._http.post('https://localhost:44305/Token',  body.toString(), options)

toString() - Serialize the body to an encoded string, where key-value pairs (separated by =) are separated by &s.

Note. Also it works without setting the headers