这是一个我定义的地方：
class Place: NSObject {
var latitude: Double
var longitude: Double
init(lat: Double,lng: Double,name: String){
self.latitude = lat
self.longitude = lng
}
required init(coder aDecoder: NSCoder) {
self.latitude = aDecoder.decodeDoubleForKey("latitude")
self.longitude = aDecoder.decodeDoubleForKey("longitude")
}
func encodeWithCoder(aCoder: NSCoder!) {
aCoder.encodeObject(latitude,forKey: "latitude")
aCoder.encodeObject(longitude,forKey: "longitude")
}
}
这是我如何保存一个地方数组：
var placesArray = [Place]
//...
func savePlaces() {
NSUserDefaults.standardUserDefaults().setobject(placesArray,forKey: "places")
println("place saved")
}
它没有工作,这是我在控制台上得到的：
Property list invalid for format: 200 (property lists cannot contain objects of type 'CFType')
我是iOS新手,可以帮我吗？
第二版
我找到了一个解决方案来保存数据：
func savePlaces(){
let myData = NSKeyedArchiver.archivedDataWithRootObject(placesArray)
NSUserDefaults.standardUserDefaults().setobject(myData,forKey: "places")
println("place saved")
}
但是当使用此代码加载数据时,我收到错误：
let placesData = NSUserDefaults.standardUserDefaults().objectForKey("places") as? NSData
if placesData != nil {
placesArray = NSKeyedUnarchiver.unarchiveObjectWithData(placesData!) as [Place]
}
错误是：
[NSKeyedUnarchiver decodeDoubleForKey:]: value for key (latitude) is not a double number'
我很确定我存档了一个Double,存在一个存储/加载过程的问题
任何线索？
解决方法
从
Property List Programming Guide：
If a property-list object is a container (that is,an array or dictionary),all objects contained within it must also be property-list objects. If an array or dictionary contains objects that are not property-list objects,then you cannot save and restore the hierarchy of data using the varIoUs property-list methods and functions.
您将需要使用NSKeyedArchiver和NSKeyedUnarchiver将对象转换为NSData实例.
例如：
func savePlaces(){
let placesArray = [Place(lat: 123,lng: 123,name: "hi")]
let placesData = NSKeyedArchiver.archivedDataWithRootObject(placesArray)
NSUserDefaults.standardUserDefaults().setobject(placesData,forKey: "places")
}
func loadplaces(){
let placesData = NSUserDefaults.standardUserDefaults().objectForKey("places") as? NSData
if let placesData = placesData {
let placesArray = NSKeyedUnarchiver.unarchiveObjectWithData(placesData) as? [Place]
if let placesArray = placesArray {
// do something…
}
}
}