ios - Cancel NSOperationsQueue -

i trying cancel nsoperationsqueue , remove operations queue. called method "cancelalloperations()" doesnt remove operation queue, aware method adds flag operation.

how go removing operations queue? or prevent operation queue executing operations have flag?

private let mediadownloadoperationqueue: nsoperationqueue = {     let queue = nsoperationqueue()     queue.maxconcurrentoperationcount = 1     queue.qualityofservice = .background      return queue }()  func startdownloadprocess() {     guard downloadswitchstate == true else { return }      let context = databasemanager.sharedinstance.mainmanagedobjectcontext     let mediastodownload = self.listofmediatodownload(context)      media in mediastodownload {         downloadmedia(media)     } }  private func downloadmedia(media: media) {     //check if operation exist     operation in mediadownloadoperationqueue.operations {         let operation = operation as! mediadownloadoperation          if operation.media.objectid == media.objectid { return }     }      //here adding operation queue     mediadownloadoperationqueue.addoperation(mediadownloadoperation(media: media)) } 

//edit: here mediasdownloadoperation

import foundation import alamofire  class mediadownloadoperation: baseasyncoperation {      let media: media     init(media: media) {         self.media = media         super.init()     }      override func main() {         guard let mediasourceuri = media.sourceuri         else {             self.completeoperation()             return         }             var filepath: nsurl?         let destination: (nsurl, nshttpurlresponse) -> (nsurl) = {             (temporaryurl, response) in              if let directoryurl = nsfilemanager.defaultmanager().urlsfordirectory(.documentdirectory, indomains: .userdomainmask).first, let suggestedfilename = response.suggestedfilename {                 filepath = directoryurl.urlbyappendingpathcomponent("\(suggestedfilename)")                 return filepath!             }         return temporaryurl     }          requestmanager.sharedalamofiremanager.download(.get, mediasourceuri, destination: destination).response {             (request, response, data, error) -> void in              if let filepath = filepath error == nil {                 let savetocameraroll = self.media.savetocameraroll?.boolvalue == true                  self.media.filelocation = filepath.lastpathcomponent                 self.media.savetocameraroll = false                  databasemanager.sharedinstance.save()                  if savetocameraroll {                     self.media.savemediatocameraroll(nil)                 }             }              self.completeoperation()             nsnotificationcenter.defaultcenter().postnotificationname(mediadownloadmanager.mediaisdownloadednote, object: nil)          }     } } 

adding conditional test see if operation has cancelled seemed have solved problem:

    requestmanager.sharedalamofiremanager.download(.get, mediasourceuri, destination: destination).response {         (request, response, data, error) -> void in          //only download if logged in         if (self.cancelled == false){             print("ran operation!")             if let filepath = filepath error == nil {                 let savetocameraroll = self.media.savetocameraroll?.boolvalue == true                  self.media.filelocation = filepath.lastpathcomponent                 self.media.savetocameraroll = false                  databasemanager.sharedinstance.save()                  if savetocameraroll {                     self.media.savemediatocameraroll(nil)                 }             }              self.completeoperation()              nsnotificationcenter.defaultcenter().postnotificationname(mediadownloadmanager.mediaisdownloadednote, object: nil)         }else{             print("did not run operation!  cancelled!")             self.completeoperation()         }     }