nsuserdefaults

问题 I made a first try to use NSUserDefaults in an App with UIPickerViews. But the App is crashing while testing / the data isn't displayed in the PickerView. I still try to fix it myself but some help would be great. ViewController3: Where the user should save data to the NSUserDefault. Therefore there is an textField to write down something and a "Savebutton" class ViewController3: UIViewController, UITextFieldDelegate { @IBOutlet weak var textField: UITextField! ... @IBAction func

问题 I made a first try to use NSUserDefaults in an App with UIPickerViews. But the App is crashing while testing / the data isn't displayed in the PickerView. I still try to fix it myself but some help would be great. ViewController3: Where the user should save data to the NSUserDefault. Therefore there is an textField to write down something and a "Savebutton" class ViewController3: UIViewController, UITextFieldDelegate { @IBOutlet weak var textField: UITextField! ... @IBAction func

问题 I've set some user defaults using let userDefaults = UserDefaults.standard , and when I'm retrieving them, I can use any of these: jobTextField.text = userDefaults.object(forKey: "job") as? String OR I can use jobTextField.text = userDefaults.value(forKey: "job") as? String in what case this will has a difference? It'd be great to know when I can NOT use one of them. Thanks a lot :) 回答1: value(forKey:) is from key-value coding, and not a direct method of UserDefaults . Never use value(forKey:

问题 There are three ways to write persistently to the device in iOS that I'm aware of: NSUserDefaults Custom Objects - Archived and Written to a PATH in NSDocuments SQLite Apple provide a mechanism to prevent iCloud backups with #2 i.e. - (BOOL)addSkipBackupAttributeToItemAtURL:(NSURL *)URL I use NSUserDefaults to store three images but to adhere to iOS Data Storage Guidelines - How do I prevent Backups with iCloud with NSUserDefaults? This question has been asked several times on SO but there is

问题 Is there a difference between UserDefaults() and UserDefaults.standard in Swift 3.0? 回答1: UserDefaults - Gives you a new object , each object is allocated a different memory and deallocated when object scope is finished. UserDefaults.standard - Gives you the singleton object by using the class method standard the object received by this method is allocated single memory throughout the application. And the usage of them if you´re interesedted in that: // Set UserDefaults.standard.set("YOUR

问题 I added App Groups to my app ID in the developer portal and am using that App ID in my provisioning profile. My Product Identifier in Xcode is set to that app ID. In my app delegate I call this from didFinishLaunchingWithOptions NSUserDefaults.standardUserDefaults().setObject("hey", forKey: "TEST") NSUserDefaults.standardUserDefaults().synchronize() In my keyboard app extension I call this: if let test = NSUserDefaults.standardUserDefaults().objectForKey("TEST") as? String { println(test) }

问题 I want to know how can I use NSDictionary in NSUserDefault ? I have to store name, points and time of user into the NSDictionary and dictionary into the user default. 回答1: NSDictionary *dict = [[NSDictionary alloc] init]; [[NSUserDefaults standardUserDefaults] setObject:dict forKey:@"dict"]; [[NSUserDefaults standardUserDefaults] synchronize]; At the time of retrieval of data, dict = [[NSUserDefaults standardUserDefaults] objectForKey:@"dict"]; 回答2: NSUserDefaults *defaults = [NSUserDefaults

问题 I want to ask about how to use NSUserDefaults on watchOS app. Is its data different from iOS app's NSUserDefaults 's data? There are a lot of stackoverflow questions about this topic and all of them have same answers. That said, for example Watch apps that shared data with their iOS apps using a shared group container must be redesigned to handle data differently. In watchOS 2, each process must manage its own copy of any shared data in the local container directory. For data that is actually

问题 I have a problem. There is class to store game progress: struct GameData { PackData & packDataById(LEVEL_PACK packId); int gameVersion; AudioData audio; PackData sunrise; PackData monochrome; PackData nature; }; //singleton @interface GameDataObject : NSObject <NSCoding> { GameData data_; } +(GameDataObject*) sharedObject; -(id) initForFirstLaunch; -(GameData*) data; -(void) save; @end and implementation: @implementation GameDataObject static GameDataObject *_sharedDataObject = nil; +

问题 To get a value from NSUserDefaults I would do something like this: let userDefaults = NSUserDefaults.standardUserDefaults() if let value = userDefaults.objectForKey(key) { print(value) } However, these methods do not return optionals: boolForKey (defaults to false if not set) integerForKey (defaults to 0 if not set) floatForKey (defaults to 0.0 if not set) doubleForKey (defaults to 0.0 if not set) In my app I want to used the saved value of an integer if it has been previously set. And if it