UIbutton Action method does not work in swift -

i creating simple video downloading app

everything work when click on download button video downloading work activity indicator not work , write msg in println not work

i add button on custom view , used swiftspinner.swift library activity indicator

here code

  @ibaction func downloadaction(sender: anyobject) {     println("hello")      swiftspinner.show("downloading...", animated: true)     let urlpath = self.photoinfo?.sourceimageurl     let urllastpath = self.photoinfo?.sourceimageurl.lastpathcomponent     var data : nsdata = nsdata(contentsofurl: urlpath!)!      var path = nssearchpathfordirectoriesindomains(nssearchpathdirectory.cachesdirectory, nssearchpathdomainmask.userdomainmask, true)[0].stringbyappendingpathcomponent(urllastpath!) string     println(path)      delay(seconds: 16.0, completion: {         swiftspinner.show("downloading completed", animated: false)     })        data.writetofile(path, atomically: true)      delay(seconds: 18.0, completion: {         swiftspinner.hide()     })      uisavevideoatpathtosavedphotosalbum(path, nil, nil, nil)  } 

here complete working code:

import uikit  class viewcontroller: uiviewcontroller {      override func viewdidload() {         super.viewdidload()         // additional setup after loading view, typically nib.     }      @ibaction func downloadaction(sender: anyobject) {         println("hello")          //spinner show when press button.          swiftspinner.show("downloading...", animated: true)         if let checkedurl = nsurl(string: "http://hdwallpaperd.com/wp-content/uploads/hd-widescreen-wallpapers-4.jpg") {             downloadimage(checkedurl)         }      }      func downloadimage(url:nsurl){         println("started downloading \"\(url.lastpathcomponent!.stringbydeletingpathextension)\".")         getdatafromurl(url) { data in              // stuff background queue              dispatch_async(dispatch_get_main_queue()) {                  swiftspinner.show("downloading completed", animated: false)                  //here can set delay can perform action after download finish.                  let delaytime = dispatch_time(dispatch_time_now, int64(2 * double(nsec_per_sec)))                 dispatch_after(delaytime, dispatch_get_main_queue()) {                      // code run after 2 second in case.                      var path = nssearchpathfordirectoriesindomains(nssearchpathdirectory.cachesdirectory, nssearchpathdomainmask.userdomainmask, true)[0].stringbyappendingpathcomponent("image1") string                     println(path)                     data!.writetofile(path, atomically: true)                     swiftspinner.hide()  // after 2 second spinner hide.                     uisavevideoatpathtosavedphotosalbum(path, nil, nil, nil)                 }             }         }     }      func getdatafromurl(url:nsurl, completion: ((data: nsdata?) -> void)) {         nsurlsession.sharedsession().datataskwithurl(url) { (data, response, error) in             completion(data: nsdata(data: data))             }.resume()     } } 

you can refer this example project.