在 Swift 5 中保存天数数组

Question

所以我创建了一个 class 的一天和一杯饮料。我正在尝试跟踪您一天喝了多少酒，但我正在努力节省多天时间。我目前正在设法保存当天（当天喝醉的量），但我不知道如何保存超过一天。

我想保存所有日期的 Day 类型数组。我该怎么做？

这是我的一天class:

public class Day: NSObject {
var date: Date
var goalAmount: Drink
var consumedAmount: Drink

func saveDay() {
    let formatting = DateFormatter()
    formatting.dateFormat = "EEEE - dd/mm/yy"
    UserDefaults.standard.set(formatting.string(from: date), forKey: "date")
    UserDefaults.standard.set(goalAmount.amountOfDrink, forKey: "goal")
    UserDefaults.standard.set(consumedAmount.amountOfDrink, forKey: "consumed")
}

func loadDay() {
    let rawDate = UserDefaults.standard.value(forKey: "date") as? String ?? ""
    let formatter = DateFormatter()
    formatter.dateFormat = "EEEE - dd/mm/yy"
    date = formatter.date(from: rawDate)!
    goalAmount.amountOfDrink = UserDefaults.standard.float(forKey: "goal")
    consumedAmount.amountOfDrink = UserDefaults.standard.float(forKey: "consumed")
}
}

这是我的饮料class：

class Drink: NSObject {
   var typeOfDrink: String
   var amountOfDrink: Float

}

我在当天有任何更改时调用 saveDay()，然后在应用程序打开时调用 loadDay()。

Answer 1

1) 您需要为此创建对象数组：

goalAmount = [Drink]()
var date = [Date]()

并追加每个新元素。您还可以在饮料中添加日期变量 class.

2) 你也可以创建字典数组：

var userData = [String : Any]()

key 将是你的约会对象，Any 中包含与饮料相关的数据，你可以存储 Anything。

Answer 2

更好的方法是将 class 的对象存储在 userDefaults 中，而不是存储 class 的特定属性。并使用 [Date] 而不是 Date 来节省多天

首先，您需要 Serialize 将对象存储在 userDefaults 中，并 Deserialize 从 userDefaults 中获取数据。

import Foundation

class Day: Codable {

    var date = Date()
    var goalAmount: Drink
    var consumedAmount: Drink

    init(date: Date, goalAmount: Drink,consumedAmount: Drink ) {
        self.date = date
        self.goalAmount = goalAmount
        self.consumedAmount = consumedAmount

    }


  static func saveDay(_ day : [Day]) {
        do {
            let object = try JSONEncoder().encode(day)
            UserDefaults.standard.set(object, forKey: "days")
        } catch {
            print(error)
        }


    }

  static func loadDay() {
        let decoder = JSONDecoder()
        if  let object = UserDefaults.standard.value(forKey: "days") as? Data {
            do {
                let days = try decoder.decode([Day].self, from: object)

                for day in days {
                    print("Date - ", day.date)
                    print("Goal Amount - ", day.goalAmount)
                    print("Consumed Amount - ",day.consumedAmount)
                    print("----------------------------------------------")
                }


            } catch {
                print(error)
            }


        } else {
            print("unable to fetch the data from day key in user defaults")
        }
    }
}


class Drink: Codable {
    var typeOfDrink: String
    var amountOfDrink: Float

    init(typeOfDrink: String,amountOfDrink: Float ) {
        self.typeOfDrink = typeOfDrink
        self.amountOfDrink = amountOfDrink
    }

}

使用 saveAndGet() 方法从 userDefaults 中存储和获取详细信息

func saveAndGet() {
 // use any formats to format the dates
        let date = Date()
        let goalAmount = Drink(typeOfDrink: "Water", amountOfDrink: 5.0)
        let consumedAmount = Drink(typeOfDrink: "Water", amountOfDrink: 3.0)

        let day1 = Day(date: date, goalAmount: goalAmount, consumedAmount: consumedAmount)
        let day2 = Day(date: date, goalAmount: goalAmount, consumedAmount: consumedAmount)
        let day3 = Day(date: date, goalAmount: goalAmount, consumedAmount: consumedAmount)
        let day4 = Day(date: date, goalAmount: goalAmount, consumedAmount: consumedAmount)

        let days = [day1, day2, day3, day4]
        Day.saveDay(days)

        Day.loadDay()
    }

在 Swift 5 中保存天数数组

Save array of Days in Swift 5

arrays

saving-data

ios

swift5