我想将类的NSArray放到cacheDirectory中.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")
}
解决方法
Xcode 7.3.1•Swift 2.2.1
您可以使您的Dog class 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,您可以将阵列数据保存到磁盘,如下所示：
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.
}
}
