ios - Cant dismiss my previous alertcontroller completely -

i trying use 1 single alert controller include multiple alert showing functions , 1 dismiss function.but having this warning in console , other alert don't show.i wonder why?and solution that.

here alert controller

import uikit  class myalertviewcontroller: uiviewcontroller {  var myalertcontroller : uialertcontroller!  override func viewdidload() {     super.viewdidload() }  override func didreceivememorywarning() {     super.didreceivememorywarning()     // dispose of resources can recreated. }  func displayloadingalert(viewcontroller: uiviewcontroller?) -> uialertcontroller {      var controllertopresent = viewcontroller     if controllertopresent == nil {         controllertopresent = self     }      //create alert controller     myalertcontroller = uialertcontroller(title: "loading...", message: “we receiving data,please wait“, preferredstyle: .actionsheet)      controllertopresent!.presentviewcontroller(myalertcontroller, animated: true, completion: nil)      return myalertcontroller }  func connectionerroralert(viewcontroller: uiviewcontroller?) -> uialertcontroller {      var controllertopresent = viewcontroller     if controllertopresent == nil {         controllertopresent = self     }      //create alert controller     myalertcontroller = uialertcontroller(title: "not connected", message: “no internet connection”, preferredstyle: .alert)     let defaultaction = uialertaction(title: "ok", style: .default,handler:nil)     myalertcontroller.addaction(defaultaction)      controllertopresent!.presentviewcontroller(myalertcontroller, animated: true, completion: nil)      return myalertcontroller }  func requesttimeouterroralert(viewcontroller: uiviewcontroller?) -> uialertcontroller {      var controllertopresent = viewcontroller     if controllertopresent == nil {         controllertopresent = self     }      //create alert controller     myalertcontroller = uialertcontroller(title: "request time out", message: “please click retry”, preferredstyle: .alert)     let defaultaction = uialertaction(title: "ok", style: .default,handler:nil)     myalertcontroller.addaction(defaultaction)      controllertopresent!.presentviewcontroller(myalertcontroller, animated: true, completion: nil)      return myalertcontroller }  func dismissloadingalert(){     myalertcontroller.dismissviewcontrolleranimated(true, completion: nil) }  } 

i use dismissloadingalert() when results api.but,when don't results api.i used delegate method protocol.

func didnotreceiveapiresults(results: bool,error:nserror){     dispatch_async(dispatch_get_main_queue(), {         // condition enter if dont results , show user alert.         if (results) {             // have done dismiss first data receiving alert,what doing wrong?             self.myalertcontroller.dismissloadingalert()             if error.localizeddescription == "the internet connection appears offline."{                 self.myalertcontroller.connectionerroralert(self)                 self.cartableview.hidden=true                 self.retrybutton?.hidden=false                 self.retrybutton?.enabled=true             }             if error.localizeddescription == "request time out."{                 self.myalertcontroller.requesttimeouterroralert(self)                 self.cartableview.hidden=true                 self.retrybutton?.hidden=false                 self.retrybutton?.enabled=true             }          }else{             self.myalertcontroller.displayloadingalert(self)             self.retrybutton?.hidden=true             self.retrybutton?.enabled=false             self.cartableview.hidden=false             self.cartableview.reloaddata()         }     }) } 

you on wrong track. should not subclass controller.

the uialertcontroller class intended used as-is , not support subclassing. view hierarchy class private , must not modified.

if need convenience class, refactor using nsobject subclass presents dynamic uialertcontroller instances.