Question

我正在编写一个应用程序，它需要每天重置存储在NSUserDefaults中的密钥。（00:00时）

我已经实现了这一点，但我使用的方法是一个混乱且不可靠的方法。

有没有简单的方法来实现我的目标？

这是代码。

    extension NSDate
    {

        func month() -> Int
        {
            let calendar = NSCalendar.currentCalendar()
            let components = calendar.components(.Month, fromDate: self)
            let month = components.month
            return month
        }


        func date() -> Int
        {
            let calendar = NSCalendar.currentCalendar()
            let components = calendar.components(.Day, fromDate: self)
            let date = components.day

            return date
        }

        func hour() -> Int
        {
            //Get Hour
            let calendar = NSCalendar.currentCalendar()
            let components = calendar.components(.Hour, fromDate: self)
            let hour = components.hour

            //Return Hour
            return hour
        }


        func minute() -> Int
        {
            //Get Minute
            let calendar = NSCalendar.currentCalendar()
            let components = calendar.components(.Minute, fromDate: self)
            let minute = components.minute

            //Return Minute
            return minute
        }

        func toShortTimeString() -> String
        {
            //Get Short Time String
            let formatter = NSDateFormatter()
            formatter.timeStyle = .ShortStyle
            let timeString = formatter.stringFromDate(self)

            //Return Short Time String
            return timeString
        }
    }


class ViewController: UIViewController {


    var totalcounterme:Int! //stored variable
    let currentDate = NSDate() //current date
    var todaysDate:Int! //date variable for storing local value




    @IBOutlet weak var todayTotal: UILabel! //total cigarrete count value

    @IBOutlet weak var numberC: UITextField! //text label value

    @IBAction func countPressed(sender: AnyObject) {
        var counter = totalcounterme //add local value to the counter
        if numberC.text != "" {
        counter = counter + Int(numberC.text!)! //add input value to counter
        numberC.text = ""
        todayTotal.text = "\(counter)" //display value of counter
        NSUserDefaults.standardUserDefaults().setInteger(counter, forKey: "storedCounter") //store counter value
        totalcounterme = NSUserDefaults.standardUserDefaults().integerForKey("storedCounter") //return stored value
        todaysDate = currentDate.date()
            if todaysDate > NSUserDefaults.standardUserDefaults().integerForKey("finaldate") {
                NSUserDefaults.standardUserDefaults().setInteger(0, forKey: "storedCounter")

            } else if todaysDate < NSUserDefaults.standardUserDefaults().integerForKey("finaldate") {
                if currentDate.month() > NSUserDefaults.standardUserDefaults().integerForKey("finalmonth") {
                    NSUserDefaults.standardUserDefaults().setInteger(0, forKey: "storedCounter")
                }
            }

        NSUserDefaults.standardUserDefaults().setInteger(todaysDate, forKey: "finaldate") //set todays date in value
        NSUserDefaults.standardUserDefaults().setInteger(currentDate.month(), forKey: "finalmonth") //set month

        }
        }



    override func viewDidLoad() {
        super.viewDidLoad()


        let month = NSUserDefaults.standardUserDefaults().integerForKey("finalmonth")
        let today = NSUserDefaults.standardUserDefaults().integerForKey("finaldate")
        if currentDate.date() > today {
            NSUserDefaults.standardUserDefaults().setInteger(0, forKey: "storedCounter")
        } else if currentDate.date() < today {
            if currentDate.month() > month {
            NSUserDefaults.standardUserDefaults().setInteger(0, forKey: "storedCounter")
            }
        }

        totalcounterme = NSUserDefaults.standardUserDefaults().integerForKey("storedCounter")

        todayTotal.text = "\(totalcounterme)"

    }
}

Answer 1

您可以使用getter和setter创建NSUserDefault扩展计算属性，以保存用户上次访问日期。 NSCalendar有一个名为isDateInToday的方法，如果上次访问日期与今天不同，您可以在setter内部使用removePersistentDomainForName：

extension UserDefaults {

    static let defaults = UserDefaults.standard

    static var lastAccessDate: Date? {
        get {
            return defaults.object(forKey: "lastAccessDate") as? Date
        }
        set {
            guard let newValue = newValue else { return }
            guard let lastAccessDate = lastAccessDate else {
                defaults.set(newValue, forKey: "lastAccessDate")
                return
            }
            if !Calendar.current.isDateInToday(lastAccessDate) {
                print("remove Persistent Domain")
                UserDefaults.reset()
            }
            defaults.set(newValue, forKey: "lastAccessDate")
        }
    }

    static func reset() {
        defaults.removePersistentDomain(forName: Bundle.main.bundleIdentifier ?? "")
    }
}

只需在用户打开应用时设置用户上次访问日期：

override func viewDidLoad() {
    super.viewDidLoad()
    UserDefaults.lastAccessDate = Date()
}

每天在Swift中重置NSUserDefault密钥

1 个答案: