将Class的NSArray保存到cacheDirectory

我想要caching目录的类的NSArray。 我写了如下，但它返回false。 你能告诉我如何解决这个问题吗？ 谢谢你的好意。

let paths2 = NSSearchPathForDirectoriesInDomains( .CachesDirectory, .UserDomainMask, true) let cachesPath: AnyObject = paths2[0] var cachedQuestions:NSArray = questions as NSArray let filePath = cachesPath.stringByAppendingPathComponent("CachedQuestions") class Dog { var id:Int? var name:String? init(id:Int, name:String) { self.id = id self.name = name } } var dogs = [Dog]() dogs.append(Dog(id:1, name:"taro")) dogs.append(Dog(id:2, name:"jiro")) var nsArrayDogs:NSArray = dogs as NSArray let success = nsArrayDogs.writeToFile(filePath, atomically: true) if success { println("save success") } 

Answer 1

Xcode 7.3.1•Swift 2.2.1

你可以让你的Dog类NSCoding兼容：

 class Dog: NSObject, NSCoding { let id: Int let name: String required init(id: Int, name: String) { self.id = id self.name = name } required init(coder decoder: NSCoder){ self.id = decoder.decodeObjectForKey("id") as? Int ?? 0 self.name = decoder.decodeObjectForKey("name") as? String ?? "" } func encodeWithCoder(coder: NSCoder) { coder.encodeObject(id, forKey: "id") coder.encodeObject(name, forKey: "name") } } 

然后你可以保存你的arrays数据到磁盘如下：

 class ViewController: UIViewController { override func viewDidLoad() { super.viewDidLoad() // Do any additional setup after loading the view, typically from a nib. let dog1 = Dog(id: 1, name: "taro") let dog2 = Dog(id: 2, name: "jiro") do { let cachesDirectoryURL = try NSFileManager.defaultManager().URLForDirectory(.CachesDirectory, inDomain: .UserDomainMask, appropriateForURL: nil, create: true) let array = [dog1, dog2] let fileURL = cachesDirectoryURL.URLByAppendingPathComponent("CachedQuestions.plist") let success = NSKeyedArchiver.archiveRootObject(array, toFile: fileURL.path!) print(success) // to load it from disk if let loadedArray = NSKeyedUnarchiver.unarchiveObjectWithFile(fileURL.path!) as? [Dog] { print(loadedArray.count) // 2 } } catch let error as NSError { print(error.localizedDescription) } } override func didReceiveMemoryWarning() { super.didReceiveMemoryWarning() // Dispose of any resources that can be recreated. } }