nskeyedarchiver

问题 Can you show me the syntax or any sample programs to archive an NSArray of custom objects in Objective-C? 回答1: Check out NSUserDefaults . For Archiving your array, you can use the following code: [[NSUserDefaults standardUserDefaults] setObject:[NSKeyedArchiver archivedDataWithRootObject:myArray] forKey:@"mySavedArray"]; And then for loading the custom objects in the array you can use this code: NSUserDefaults *currentDefaults = [NSUserDefaults standardUserDefaults]; NSData *savedArray =

问题 I have an array of CLLocation data that I would like to archive. Should the NSUserDefaults system be used? Otherwise, how best to archive the CLLocation data? 回答1: UserDefaults can only store certain types of data, and should be used to store user preference information, not arbitrary application state data. To quote the Apple docs: The NSUserDefaults class provides a programmatic interface for interacting with the defaults system. The defaults system allows an application to customize its

问题 I was wondering whether or not it is possible to use the NSCoder method: - (void)encodeObject:(id)objv forKey:(NSString *)key to encode either an instance of NSArray or NSDictionary. If not how do you go about encoding them? I am trying to use NSKeyedArchived / NSKeyedUnarchiver to send data between phones using GameKit. I tried it and cannot seem to retrieve the string I stored in my array. The packet class I made comes through along with the packet type integer, but not the data in the

问题 I'm trying to store an Integer and retrieve it using KeyChain. This is how I save it: func SaveNumberOfImagesTaken() { let key = "IMAGE_TAKEN" var taken = 10 let data = NSKeyedArchiver.archivedDataWithRootObject(taken) let query : [String:AnyObject] = [ kSecClass as String : kSecClassGenericPassword, kSecAttrAccount as String : key, kSecValueData as String : data ] let status : OSStatus = SecItemAdd(query as CFDictionaryRef, nil) } This is how I try to retrieve it: func

问题 I'm trying to store an Integer and retrieve it using KeyChain. This is how I save it: func SaveNumberOfImagesTaken() { let key = "IMAGE_TAKEN" var taken = 10 let data = NSKeyedArchiver.archivedDataWithRootObject(taken) let query : [String:AnyObject] = [ kSecClass as String : kSecClassGenericPassword, kSecAttrAccount as String : key, kSecValueData as String : data ] let status : OSStatus = SecItemAdd(query as CFDictionaryRef, nil) } This is how I try to retrieve it: func

问题 I am making an iPhone app and in a previous question I was told that I needed a valid file path for archiverootobject and unarchiverootobject but I don't know how to make one. So what is a valid file path to save arrays of custom classes? Follow up question: On the linked question I have set up my methods to use invalid saves but it still works would anyone know why? 回答1: You can save it to a subdirectory folder named with your bundleID inside the application support folder or you can also

问题 Previously, I have an array in which I use NSKeyedArchiver to archieve. [NSKeyedArchiver archiveRootObject:array toFile:docPath]; Called on applicationWillTerminate and applicationDidEnterBackground . Upon starting up, in didFinishLaunchingWithOPtions , the array is unarchieved: NSMutableArray *array = [NSKeyedUnarchiver unarchiveObjectWithFile:docPath]; Everything was good. Since then, I added a Singleton class for Settings variables. I would like to archive the Singleton as well. How would

问题 I'm having trouble setting up a model object to save the visual state of user generated CALayers in a simple graphics application for the iphone. I'm attempting to save the background color and frame of all the current layers on screen by passing those properties to model objects which implement the NSCoding protocol and then into an NSMutableArray which the app delegate owns. Then I archive the array with NSKeyedArchiver and store it in the NSUserDefaults. Each CALayer's backgroundColor

问题 I have a class that I've made into a singleton and am able to save it's state using an NSKeyedArchiver, but I can't wrap my head around pulling it's state back out. In the function that does the loading I have Venue *venue = [Venue sharedVenue]; NSData *data = [[NSMutableData alloc] initWithContentsOfFile:[self dataFilePath]]; NSKeyedUnarchiver *unarchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:data]; venue = [unarchiver decodeObjectForKey:@"Venue"]; [unarchiver finishDecoding];

问题 I'm currently looking for the best way to save data in my iPhone application; data that will persist between opening and closing of the application. I've looked into archiving using a NSKeyedArchiver and I have been successful in making it work. However, I've noticed that if I try to save multiple objects, they keep getting overwritten every time I save. (Essentially, the user will be able to create a list of things he/she wants, save the list, create a few more lists, save them all, then be