uiapplicationdelegate

问题 I have an application in which i have set a local notification in my class.m file which is show below:- -(IBAction)save{ NSString *str1=[NSString stringWithFormat:@"%@",txt_date.text]; NSString *str2=[NSString stringWithFormat:@" %@",txt_time.text]; str1=[str1 stringByAppendingFormat:str2]; selected_label.text= str1; [[UIApplication sharedApplication] cancelAllLocalNotifications]; NSDate *today=[NSDate date]; NSDateFormatter* formatter_current = [[[NSDateFormatter alloc] init] autorelease];

问题 I have an iOS application which uses local notifications. When the app is running in the background or is active, I use the application didReceiveLocalNotification methods and that works great. But when the app is closed (not running in the background), I use the application didFinishLaunchingWithOptions method to control what happens when the notification is handled. However, the problem I have is that the notification is always (null) in the didFinishLaunchingWithOptions method. Here is my

问题 I'm using GCD's dispatch_after method when my application is being loaded to perform some behavior. The intended behavior is to wait 3 seconds from the end of applicationDidFinishLaunchingWithOptions to perform a selector that runs in a background queue. I haven't experienced any crashes on my test devices, but I have user crash reports of uncaught SIGBUS signals, the cause being a BUS_ADRALN exception. From my understanding of this code, a BUS_ADRALN error indicates an address alignment

问题 Instead of using an application delegate so that the UIApplication singleton can call the delegate methods at predefined time, what are the advantages and disadvantages of just subclassing UIApplication ? ( update: why does the iOS architecture use the application delegate instead of letting people write an application by subclassing UIApplication and overriding its various methods?) That's because when we create a new UIView control, we subclass UIView ( update: or we subclass

问题 I wonder if it's possible to quit my program entirely after the user presses the Home button, rather than going into background run mode. Thanks. 回答1: In your application's Info.plist , add a boolean key UIApplicationExitsOnSuspend with the value YES . See the Information Property List Key Reference for more information. 回答2: Yup!! Although Apple will warn you that they don't want you to do this, it is possible, and I will trust that whatever reasons you have are legitimate. They will not

问题 I have the following code in application didFinishLaunchingWithOptions where I want to present a modal view controller for user login. LoginViewController_iPhone *loginViewController=[[LoginViewController_iPhone alloc]initWithNibName:@"LoginViewController_iPhone" bundle:nil]; UINavigationController *loginNavigationController=[[UINavigationController alloc]initWithRootViewController:loginViewController]; loginNavigationController.modalPresentationStyle=UIModalPresentationFullScreen; [self

问题 Hey I got a pretty low interval timer in my firstViewController which I would like to terminate when the app enters background, but how am I supposed to access it from my Applications AppDelegate file where the function is located. I know this is extremely dumb question, but I would appreciate help. Thanks! 回答1: In your firstViewController, you would listen for UIApplicationDidEnterBackgroundNotification. In the firstViewController init method: - (void)addObserver:(id)notificationObserver

问题 Spare me if you find this too basic and generic. But i hope answering would benefit lot of noobs out there like me. Why we set Delegate to self? Thanks, Taimur 回答1: You call a pizza parlor (object) and order a large pepperoni pizza (message). The pizza parlor want to know who to call back (delegate) to say the pizza is on the way. You give them your own number (self). 回答2: For example, a UITable has two delegates, UITableDelegate and UITableDataSource... Let's say, you want to subclass a

问题 Will the UIApplicationDelegate call performFetchWithCompletionHandler if device is not connected to the internet ? The documentation isn't clear in this case. 回答1: After some tests I can claim that performFetchWithCompletionHandler delegate method is not called if device is not connected to the internet. Tested on iOS8 and iOS9. 回答2: -application:performFetchWithCompletionHandler: isn't called when a download has completed. It's called by the system to give your app a chance to download data.

问题 I have requirement for an application which work in background only. When first time application install on device then after installation that will be go to background. And after two minutes a view will popup on screen. Now problem is that after installation how to redirect application into background? i get answer for this that if we want to send our app into background then we have to open another app like as safari. so i get this solution. Now problem is that how show a view after two