ios - 核心数据: How to check if data is in consecutive dates?

Question

我在用户完成“锻炼”后保存核心数据，并希望能够检查用户锻炼的日期是否按连续顺序排列。我使用下面的代码来检查用户是否在日历上单击的一天进行了锻炼，但无法想象如何检查这些天是否连续。

起初我想获取保存的 NSDate 的 .Day 并查看日期是否按顺序排列，但是当月份发生变化时，这对于连续几天不起作用，例如每月 31 日至 1 日。

let appDel: AppDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
let context: NSManagedObjectContext = appDel.managedObjectContext

OuterLoop:  do {
    let request = NSFetchRequest(entityName: "Workout")
    let workoutResults = try context.executeFetchRequest(request) as! [Workout]

    if workoutResults.count > 0 {
        for item in workoutResults {
            let workoutDateDay = NSCalendar.currentCalendar().component(.Day, fromDate: item.workoutDate!)

            if workoutDateDay == dayView.date.day {

                let convertedTime:Int = Int(item.workoutTime!)
                let convertedNumberOfWorkouts: Int = Int(item.workoutNumber!)
                tempArray.append(convertedTime)
                tempArrayWorkoutNumber.append(convertedNumberOfWorkouts)

Answer 1

func consecutiveDatesCheck(dateArray: [NSDate]) -> Int {

    // The incoming parameter dateArray is immutable, so first make it mutable
    var mutableArray = dateArray

    // Next, sort the incoming array
    mutableArray.sortInPlace({ $0.compare($1) == NSComparisonResult.OrderedAscending })

    var x = 0
    var numberOfConsecutiveDays = 1
    var streakArray = [Int]()

    // Cycle through the array, comparing the x and x + 1 elements
    while x + 1 < mutableArray.count {

        let calendar: NSCalendar = NSCalendar.currentCalendar()
        let components = calendar.components(.Day, fromDate: mutableArray[x], toDate: mutableArray[x + 1], options: [])

        // If the difference between the dates is greater than 1, append the streak to streakArray and reset the counter
        if abs(components.day) > 1 {
            streakArray.append(numberOfConsecutiveDays)
            numberOfConsecutiveDays = 1
        }

        // If the difference between the days is exactly 1, add one to the current streak
        else if abs(components.day) == 1 {
            numberOfConsecutiveDays += 1
        }

        x += 1
    }

    // Append the final streak to streakArray
    streakArray.append(numberOfConsecutiveDays)
    print(streakArray)

    // Return the user's longest streak
    return streakArray.maxElement()!
}

然后调用函数时:

   do {
        let request = NSFetchRequest(entityName: "Workout")
        let workoutResults = try context.executeFetchRequest(request) as! [Workout]

        if workoutResults.count > 0 {

            // Declare a new empty array
            var dateArray = []

            for item in workoutResults {
                dateArray.append(item.workoutDate!)
            }

            consecutiveDatesCheck(dateArray)
        }
    } catch {
        print("Error loading data")
    }