Swift - 使用POST登录PHP

Question

I'm trying to figure out why this code takes so long to log in. It currently works, but it's just really really slow. My console shows that it's receiving the success response right away but it still doesn't go to the next view controller for awhile. I also found that after I added the code to dismiss the loading indicator it immediately closes too. So right now if I provide proper credentials it will close the loading indicator but still wait like 15 seconds before going to the next view controller. Ideas?

        let request = NSMutableURLRequest(URL: NSURL(string: "myurl")!)
        request.HTTPMethod = "POST"
        var postString = "user=\(username.text)&pass=\(password.text)"
        var success = 0

        var alert = UIAlertView(title: "Logging In", message: "Please wait...", delegate: self, cancelButtonTitle: "Cancel");


        var loadingIndicator = UIActivityIndicatorView(frame: CGRectMake(50, 10, 37, 37)) as UIActivityIndicatorView
        loadingIndicator.center = self.view.center;
        loadingIndicator.hidesWhenStopped = true
        loadingIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.Gray
        loadingIndicator.startAnimating();

        alert.setValue(loadingIndicator, forKey: "accessoryView")
        loadingIndicator.startAnimating()

        alert.show();

        request.HTTPBody = postString.dataUsingEncoding(NSUTF8StringEncoding)
        let task = NSURLSession.sharedSession().dataTaskWithRequest(request) {
            data, response, error in

            if error != nil {
                let alert = UIAlertView()
                alert.title = "Login Failed!"
                alert.message = "Error: \(error)"
                alert.delegate = self
                alert.addButtonWithTitle("OK")
                alert.show()
                return
            }

            println("response = \(response)")
            let responseString = NSString(data: data, encoding: NSUTF8StringEncoding) as! String
            println("responseString = \(responseString)")

            let jsonData = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers , error: nil) as! NSDictionary
            success = jsonData["Success"] as! Int

            if(success == 1){
                alert.dismissWithClickedButtonIndex(0, animated: true)
                self.login()
            }
            else{
                let alert = UIAlertView()
                alert.title = "Login Failed"
                alert.message = "Invalid username/password"
                alert.delegate = self
                alert.addButtonWithTitle("Retry")
                alert.show()
            }

        }

        task.resume()