ios - Back button position on navigation controller -

i'm trying develop custom search ios app.

i have managed search controller appearing , search bar appearing properly, although problem need button appear on right of navigation bar rather left, see below

(as can see button on left need on right) http://imgur.com/qlpoifg

here code:

import uikit 

class searchtop10controller: uitableviewcontroller, uisearchresultsupdating {

override func viewdidload() {     super.viewdidload()      let searchcontroller = uisearchcontroller(searchresultscontroller: self);      self.definespresentationcontext = true;     searchcontroller.searchresultsupdater = self;     //        searchcontroller.hidesnavigationbarduringpresentation = true;      searchcontroller.dimsbackgroundduringpresentation = false;     searchcontroller.searchbar.sizetofit();     self.navigationitem.titleview = searchcontroller.searchbar;     self.tableview.tableheaderview = searchcontroller.searchbar; }  override func viewdidappear(animated: bool) {   }  func updatesearchresultsforsearchcontroller(searchcontroller: uisearchcontroller) {     //do whatever searchcontroller here. }  override func didreceivememorywarning() {     super.didreceivememorywarning()     // dispose of resources can recreated. } 

you can add button right bar item this:

let backbutton : uibarbuttonitem = uibarbuttonitem(image: uiimage(named: "back_icon"), style: uibarbuttonitemstyle.plain, target: self, action: #selector(back)) self.navigationitem.rightbarbuttonitem = backbutton 

where back_icon image using , back following function:

func back() {     self.navigationcontroller?.popviewcontrolleranimated(true) } 

to hide left bar item:

self.navigationitem.leftbarbuttonitem = nil 

or:

self.navigationitem.hidesbackbutton = true