angularjs - Angular 2 - simple HTTP GET from component not working -

i have angular 2 app has simple component (see below). makes simple call web api endpoint. can call end point using postman when component tries fails. call never made , no errors output. have done wrong? i've followed pattern before.

import { component, input }  '@angular/core'; import { router_directives, router } '@angular/router'; import { http,response, headers, requestoptions  } '@angular/http'; import { domsanitizationservice } '@angular/platform-browser'; import { observable } 'rxjs/observable'; import { itile } '../interfaces/tile';  @component({     selector: 'tile',     template: require('../tile/tile.component.html'),     styles: [require('../tile/tile.component.css').tostring()],      directives: [router_directives] })  export class tilecomponent {     @input() tile: itile;      constructor(private _http: http) { }      onselect(id: string) {         this.getprofileimage(id);     }      getprofileimage(id: string): observable<string> {       let url = 'http://localhost:2116/api/profileimage/5/';      let headers = new headers({ 'accept': 'application/json' });      let options = new requestoptions({ headers: headers });      return this._http.get(url, options)             .map((response: response) => <string>response.json())             .catch(this.handleerror);      }        private handleerror(error: response) {         console.log(error);         return observable.throw(error.json().error || 'server error');     }  } 

the end point looks this...

[allowanonymous] [route("api/profileimage/{userid}")] public httpresponsemessage get(string userid) {      return request.createresponse(httpstatuscode.ok, "success"); } 

you need subscribe method (a cold observable) fire call.