通过KeyChain保存和检索值

Question

我正在尝试存储一个Integer并使用KeyChain对其进行检索。

这是我如何保存它：

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)

    }

这是我尝试检索它的方式：

func CheckIfKeyChainValueExitss() -> AnyObject? {
    var key = "IMAGE_TAKEN"
    let query : [String:AnyObject] = [
        kSecClass as String       : kSecClassGenericPassword,
        kSecAttrAccount as String : key,
        kSecReturnData as String  : kCFBooleanTrue,
        kSecMatchLimit as String  : kSecMatchLimitOne ]

    var dataTypeRef :Unmanaged<AnyObject>?

    let status: OSStatus = SecItemCopyMatching(query, &dataTypeRef)

    if let op = dataTypeRef?.toOpaque() {
        let data = Unmanaged<NSData>.fromOpaque(op).takeUnretainedValue()
        if let string: AnyObject? =  NSKeyedUnarchiver.unarchiveObjectWithData(data) as? AnyObject? {
            if key == "IMAGE_TAKEN"
            {
                return string as! String!

            }
            else if string == nil
            {
                return nil
            }
        }
    }
    return nil

}

我收到以下错误：

无法将类型’__NSCFNumber’的值强制转换为’NSString’

我尝试使用变量，但没有成功。

Answer 1

好吧，我只是用光了源代码等，并做了自己的好帮手：尽情享受吧！

 class func save(key: String, data: NSData) {
        let query = [
            kSecClass as String       : kSecClassGenericPassword as String,
            kSecAttrAccount as String : key,
            kSecValueData as String   : data ]

        SecItemDelete(query as CFDictionaryRef)

        let status: OSStatus = SecItemAdd(query as CFDictionaryRef, nil)

    }

    class func load(key: String) -> NSData? {
        let query = [
            kSecClass as String       : kSecClassGenericPassword,
            kSecAttrAccount as String : key,
            kSecReturnData as String  : kCFBooleanTrue,
            kSecMatchLimit as String  : kSecMatchLimitOne ]

        var dataTypeRef :Unmanaged<AnyObject>?

        let status: OSStatus = SecItemCopyMatching(query, &dataTypeRef)

        if status == noErr {
            return (dataTypeRef!.takeRetainedValue() as! NSData)
        } else {
            return nil
        }


    }

    class func stringToNSDATA(string : String)->NSData
    {
        let _Data = (string as NSString).dataUsingEncoding(NSUTF8StringEncoding)
        return _Data!

    }


    class func NSDATAtoString(data: NSData)->String
    {
        var returned_string : String = NSString(data: data, encoding: NSUTF8StringEncoding)! as String
        return returned_string
    }

    class func intToNSDATA(r_Integer : Int)->NSData
    {

            var SavedInt: Int = r_Integer
            let _Data = NSData(bytes: &SavedInt, length: sizeof(Int))
        return _Data

    }
    class func NSDATAtoInteger(_Data : NSData) -> Int
    {
            var RecievedValue : Int = 0
            _Data.getBytes(&RecievedValue, length: sizeof(Int))
            return RecievedValue

    }
    class func CreateUniqueID() -> String
    {
        var uuid: CFUUIDRef = CFUUIDCreate(nil)
        var cfStr:CFString = CFUUIDCreateString(nil, uuid)

        var nsTypeString = cfStr as NSString
        var swiftString:String = nsTypeString as String
        return swiftString
    }

    //EXAMPLES
//    
//    //Save And Parse Int


//    var Int_Data = KeyChain.intToNSDATA(555)
//    KeyChain.save("MAMA", data: Int_Data)
//    var RecievedDataAfterSave = KeyChain.load("MAMA")
//    var NSDataTooInt = KeyChain.NSDATAtoInteger(RecievedDataAfterSave!)
//    println(NSDataTooInt)
//    
//    
//    //Save And Parse String


//    var string_Data = KeyChain.stringToNSDATA("MANIAK")
//    KeyChain.save("ZAHAL", data: string_Data)
//    var RecievedDataStringAfterSave = KeyChain.load("ZAHAL")
//    var NSDATAtoString = KeyChain.NSDATAtoString(RecievedDataStringAfterSave!)
//    println(NSDATAtoString)