I'm trying to recieve data from a server to initialize my app. However sometimes due to the network problem I cannot recieve any data. So at this time, I need to show an alert and exit the app. Here's my code:override func viewDidLoad() { super.viewDidLoad() / var params = Dictionary<String, String>(); params[path] = /; let response = ApiRequest.get(ApiRequest.LIST_FOLDER, params: params); if (response?.objectForKey(succ) == nil) { self.presentViewController(UIAlertController.init(title: Network Error, message: No recieved data, preferredStyle: UIAlertControllerStyle.Alert), animated: true, completion: nil); abort(); } if (response?.objectForKey(succ) as! String == 0) { UIAlertView(title: Server Error, message: Unable to process the request, delegate: nil, cancelButtonTitle: Cancel).show(); abort(); } folderList = FolderList(folders: response?.objectForKey(msg) as! NSDictionary); }But actually no alert view was shown when no network connection. Anybody knows why this happened?PS: if I