如何存储我在NSUserDefaults中创建的Goal类型的对象数组？ （快速）
以下是代码：
func saveGoalList ( newGoalList : [Goal] ){
let updatedGoalList = newGoalList;
NSUserDefaults.standardUserDefaults().setObject(updatedGoalList, forKey: "GoalList")
NSUserDefaults.standardUserDefaults().synchronize()
}
class GoalsViewController: MainPageContentViewController, UITableViewDelegate, UITableViewDataSource {
@IBOutlet var tableView: GoalsTableView!
var cell = GoalTableViewCell()
var goalsArray : Array<Goal> = [] //
override func viewDidLoad() {
super.viewDidLoad()
self.tableView.delegate = self
self.tableView.dataSource = self
if var storedGoalList: [Goal] = NSUserDefaults.standardUserDefaults().objectForKey("GoalList") as? [Goal]{
goalsArray = storedGoalList;
}
var goal = Goal(title: "Walk the Dog")
goalsArray.append(goal)
saveGoalList(goalsArray)
self.tableView?.reloadData()
tableView.estimatedRowHeight = 44.0
tableView.rowHeight = UITableViewAutomaticDimension
self.xpnotificationView.alpha = 0.0
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return goalsArray.count //to ensure there is always an extra cell to fill in.
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell { //recreate the cell and try using it.
cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath) as GoalTableViewCell
cell.goalTextField.text = goalsArray[indexPath.row].title as String!
cell.checkmarkImageView.visible = goalsArray[indexPath.row].checkmarked as Bool!
if (cell.checkmarkImageView.visible == true) {
cell.blackLineView.alpha = 1.0
} else {
cell.blackLineView.alpha = 0.0
}
return cell
}
}
据我所知，只有某些数据类型适用于NSUserDefaults。谁能帮我理解我怎么能这样做？
编辑：现在，Goal继承自NSObject。
答案 0 :(得分：7)
我正在使用NSCoding从学习项目中发布代码来存储对象。功能齐全，随时可用。一个存储游戏变量等的数学游戏。
//********This class creates the object and properties to store********
import Foundation
class ButtonStates: NSObject {
var sign: String = "+"
var level: Int = 1
var problems: Int = 10
var time: Int = 30
var skipWrongAnswers = true
func encodeWithCoder(aCoder: NSCoder!) {
aCoder.encodeObject(sign, forKey: "sign")
aCoder.encodeInteger(level, forKey: "level")
aCoder.encodeInteger(problems, forKey: "problems")
aCoder.encodeInteger(time, forKey: "time")
aCoder.encodeBool(skipWrongAnswers, forKey: "skipWrongAnswers")
}
init(coder aDecoder: NSCoder!) {
sign = aDecoder.decodeObjectForKey("sign") as String
level = aDecoder.decodeIntegerForKey("level")
problems = aDecoder.decodeIntegerForKey("problems")
time = aDecoder.decodeIntegerForKey("time")
skipWrongAnswers = aDecoder.decodeBoolForKey("skipWrongAnswers")
}
override init() {
}
}
//********Here is the data archiving and retrieving class********
class ArchiveButtonStates:NSObject {
var documentDirectories:NSArray = []
var documentDirectory:String = ""
var path:String = ""
func ArchiveButtons(#buttonStates: ButtonStates) {
documentDirectories = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)
documentDirectory = documentDirectories.objectAtIndex(0) as String
path = documentDirectory.stringByAppendingPathComponent("buttonStates.archive")
if NSKeyedArchiver.archiveRootObject(buttonStates, toFile: path) {
//println("Success writing to file!")
} else {
println("Unable to write to file!")
}
}
func RetrieveButtons() -> NSObject {
var dataToRetrieve = ButtonStates()
documentDirectories = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)
documentDirectory = documentDirectories.objectAtIndex(0) as String
path = documentDirectory.stringByAppendingPathComponent("buttonStates.archive")
if let dataToRetrieve2 = NSKeyedUnarchiver.unarchiveObjectWithFile(path) as? ButtonStates {
dataToRetrieve = dataToRetrieve2 as ButtonStates
}
return(dataToRetrieve)
}
}
the following is in my ViewController where the game is played. Only showing the relevant code for retrieving and storing objects
class mathGame: UIViewController {
var buttonStates = ButtonStates()
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
//set inital view
//retrieving a stored object & placing property into local class variables
buttonStates = ArchiveButtonStates().RetrieveButtons() as ButtonStates
gameData.sign = buttonStates.sign
gameData.level = buttonStates.level
gameData.problems = buttonStates.problems
gameData.time = buttonStates.time
}
override func viewWillDisappear(animated: Bool) {
super.viewWillDisappear(animated)
//storing the object
ArchiveButtonStates().ArchiveButtons(buttonStates: buttonStates)
}
}
答案 1 :(得分：6)
您需要您的班级采用NSCoding协议并对其进行编码和解码，如下所示：
现在，您可以通过调用NSKeyedArchiver.archivedDataWithRootObject:将类的实例转换为NSData，并且NSData可以进入NSUserDefaults。
这也意味着您的类的NSArray实例可以通过相同的方式转换为NSData。
答案 2 :(得分：1)
对于 Swift 2.1 ，您的Goal类应如下所示：
import Foundation
class Goal : NSObject, NSCoding {
var title: String
// designated initializer
init(title: String) {
self.title = title
super.init() // call NSObject's init method
}
// MARK: - comply wiht NSCoding protocol
func encodeWithCoder(aCoder: NSCoder) {
aCoder.encodeObject(title, forKey: "GoalTitle")
}
required convenience init?(coder aDecoder: NSCoder) {
// decoding could fail, for example when no Blog was saved before calling decode
guard let unarchivedGoalTitle = aDecoder.decodeObjectForKey("GoalTitle") as? String
else {
// option 1 : return an default Blog
self.init(title: "unknown")
return
// option 2 : return nil, and handle the error at higher level
}
// convenience init must call the designated init
self.init(title: unarchivedGoalTitle)
}
}
你应该像在我的测试代码中那样在你的视图控制器中使用它：
// create an array with test data
let goal1 = Goal(title: "first goal")
let goal2 = Goal(title: "second goal")
let goalArray = [goal1, goal2]
// first convert the array of custom Goal objects to a NSData blob, as NSUserDefaults cannot handle arrays of custom objects directly
let dataBlob = NSKeyedArchiver.archivedDataWithRootObject(goalArray)
// this NSData object can now be stored in the user defaults
NSUserDefaults.standardUserDefaults().setObject(dataBlob, forKey: "myGoals")
// sync to make sure they are saved before we retreive anytying
NSUserDefaults.standardUserDefaults().synchronize()
// now read back
if let decodedNSDataBlob = NSUserDefaults.standardUserDefaults().objectForKey("myGoals") as? NSData {
if let loadedGoalsArray = NSKeyedUnarchiver.unarchiveObjectWithData(decodedNSDataBlob) as? [Goal] {
for goal in loadedGoalsArray {
print("goal : \(goal.title)")
}
}
}
最后一点：使用NSKeyedArchiver而不是NSUserDefaults更容易，并将自定义对象数组直接存储到文件中。您可以在我发布的另一个答案here中详细了解这两种方法之间的区别。