android - Big styled picture not showing in my notification -

i implementing big picture view notification in android. first download imagefile using async task class , pushes downloaded image notification method. picture able download servers(because shows downloaded picture in .setlargeicon) unable show in big style format.

below have done

   private class notification extends asynctask<string, void, bitmap> {  context c; string message;  public notification(context context) {     super();     this.c = context; }  @override protected bitmap doinbackground(string... params) {      inputstream in;     string urls="http//myimagefile";     try {  url url = new url(urls); httpurlconnection connection = (httpurlconnection) url.openconnection(); connection.setdoinput(true); connection.connect(); in = connection.getinputstream(); bitmap mybitmap = bitmapfactory.decodestream(in); return mybitmap;         } catch (malformedurlexception e) {         e.printstacktrace();     } catch (ioexception e) {         e.printstacktrace();     }     return null; }  @override protected void onpostexecute(bitmap result) {      super.onpostexecute(result);     try {         notificationmanager notificationmanager = (notificationmanager) c                 .getsystemservice(context.notification_service);          intent intent = new intent(c, news.class);         intent.putextra("alliswell", false);           notification notification = new notificationcompat.builder(c)         .setcontenttitle("title")         .setcontenttext("message")         .setsmallicon(r.drawable.ic_launcher)         .setlargeicon(result) // downloaded bitmap able show here         .setstyle(new notificationcompat.bigpicturestyle()             .bigpicture(result)) // unable show in format     .build();           // hide notification after selected         notification.flags |= notification.flag_auto_cancel;          notificationmanager.notify(1, notification);      } catch (exception e) {         e.printstacktrace();     } } } 

update

i thinking maybe image size not expected displayed in notification box. tried .setstyle(new notification.bigtextstyle().bigtext(averylongstring)), didnt work. think might doing wrong. wish me out because have implement functions correctly source (http://developer.android.com/reference/android/support/v4/app/notificationcompat.bigtextstyle.html) none seems work.

please doing wrong in above codes, grateful know, soo much.