Angular2-Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource

Question

I am calling a http post in Angular 2. This is working fine in post man but when I implement this API call in Angular 2 I get No 'Access-Control-Allow' error. Here is my code

getInspections(): Observable<IInspection[]> {
        if (!this.inspections) {
            let body =JSON.stringify({"Statuses":["Submitted", "Opened"]});
            let headers = new Headers({ 'Content-Type': 'application/json' });

            headers.append('Access-Control-Allow-Origin','*');
            let options = new RequestOptions({ headers: headers });

            return this.http.post(this._baseUrl + '/api/Inspect/ListI',body,options)
                .map((res: Response) => {
                    this.inspections = res.json();
                    return this.inspections;
                })
                .catch(this.handleError);
        }
        else {
            //return cached data
            return this.createObservable(this.inspections);
        }
    }

Or can I do this? Just pass header instead of options

getInspections(): Observable<IInspection[]> {
        if (!this.inspections) {
            let body =JSON.stringify({"Statuses":["Submitted", "Opened"]});
            let headers = new Headers({ 'Content-Type': 'application/json' });

            //headers.append('Access-Control-Allow-Origin','*');
          //  let options = new RequestOptions({ headers:headers });

            return this.http.post(this._baseUrl + '/api/Inspect/ListI',body,headers)
                .map((res: Response) => {
                    this.inspections = res.json();
                    return this.inspections;
                })
                .catch(this.handleError);
        }
        else {
            //return cached data
            return this.createObservable(this.inspections);
        }
    }

Answer 1

CORS headers like

headers.append('Access-Control-Allow-Origin','*');

need to be provided by the server. Adding them on the client is pointless.