nsnotificationcenter

问题 I have the following code within AppDelegate. The purpose being to create a couple of observers, and then call some code. Once that code completes it then posts a notification, and the observer should then remove both observers and call the completion handler. My issue is that it appears that the observers are not being removed as I expected. The notification is posted, and the NSLog entry is written to console, so I know that the observer is working. However, on the second time of calling,

问题 I have the following code within AppDelegate. The purpose being to create a couple of observers, and then call some code. Once that code completes it then posts a notification, and the observer should then remove both observers and call the completion handler. My issue is that it appears that the observers are not being removed as I expected. The notification is posted, and the NSLog entry is written to console, so I know that the observer is working. However, on the second time of calling,

问题 I am trying to check if device's charging port is working fine. There are two scenarios - a. when the charging cable is already plugged in. b. when the charging cable is plugged in after sometime. For case a, on viewDidLoad() I checked for enable batteryStateMonitoring and checked the current state of the battery. - It always works. For case b, I tried using NSNotification s UIDeviceBatteryStateDidChangeNotification override func viewDidLoad() { UIDevice.current.isBatteryMonitoringEnabled =

问题 I am trying to check if device's charging port is working fine. There are two scenarios - a. when the charging cable is already plugged in. b. when the charging cable is plugged in after sometime. For case a, on viewDidLoad() I checked for enable batteryStateMonitoring and checked the current state of the battery. - It always works. For case b, I tried using NSNotification s UIDeviceBatteryStateDidChangeNotification override func viewDidLoad() { UIDevice.current.isBatteryMonitoringEnabled =

问题 I've got a UITableviewController with following logic to slide up / down the entire view once the keyboard toggles like so: class ChatDetailViewController: UIViewController, UITableViewDelegate, UITableViewDataSource { // variables... override func viewDidLoad() { super.viewDidLoad() // do stuff... NotificationCenter.default.addObserver(self, selector: Selector(("keyboardWillShow:")), name: UIResponder.keyboardWillShowNotification, object: nil) NotificationCenter.default.addObserver(self,

问题 Will this category method allow me to avoid additional retains on NSNotificationCenter observers? #import "NSNotificationCenter+Util.h" @implementation NSNotificationCenter (Util) - (void)addWeakObserver:(nonnull NSObject*)observer selector:(nonnull SEL)aSelector name:(nullable NSString *)aName object:(nullable id)anObject { __weak NSObject *weakObserver = observer; [self addObserver:weakObserver selector:aSelector name:aName object:anObject]; } @end The goal is to have the object die without

问题 I am getting an error in my app that I have no idea of how to figure out, has anyone seen this before: # Binary Image Name Address Symbol 0 RepZio 0x002bd302 testflight_backtrace 1 RepZio 0x002bc996 TFSignalHandler 2 libsystem_platform.dylib 0x39ce0062 _sigtramp 3 CoreFoundation 0x2edde118 __CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ 4 CoreFoundation 0x2ed52256 _CFXNotificationPost 5 Foundation 0x2f737c2c -[NSNotificationCenter postNotificationName:object:userInfo:] 6 Foundation

问题 Can I use the selector getUpdate: in multiple view controllers? I'm registering my LevelViewController as an observer for both GameViewController and WinViewController . The latter 2 view controllers both have a back button (which, when pressed, pops you back to LevelVC ), and the idea with the notification is to tell LevelVC whether or not to update the collection view cells (via the viewWillAppear: method) when the back button is pressed. In viewWillAppear: , I wouldn't want to call two

问题 I am sending a notification from one view to another view. My problem is that the notification in the view that I am calling in my cellForRowAtIndexPath method is only getting sent when the tableview is scrolling. How can I stop this and make it send the notification once the images have downloaded? Here is my code: https://gist.github.com/756302 Thanks MKDev 回答1: as far as I understand your code, the message will trigger the reload of the whole table. That should lead to a refresh of the

问题 I can't receive a notification with this: a class for doing NSURLConnection async stuff - (void)connectionDidFinishLoading:(NSURLConnection *)connection { NSDictionary *userInfo = [NSDictionary dictionaryWithObjectsAndKeys:_receivedData, @"receivedData", nil]; [[NSNotificationCenter defaultCenter] postNotificationName:kWebServiceURLTemperaturaMaximaKMLNotitificationName object:self userInfo:userInfo]; } another class observing the notification: [[NSNotificationCenter defaultCenter]