如何检查两个NSDate是否来自同一天[重复]

Question

我正在开发 ios，我发现很难检查两个 NSDate 是否来自同一天。我试过用这个

   fetchDateList()
    // Check date
    let date = NSDate()
    // setup date formatter
    let dateFormatter = NSDateFormatter()
    // set current time zone
    dateFormatter.locale = NSLocale.currentLocale()

    let latestDate = dataList[dataList.count-1].valueForKey("representDate") as! NSDate
    //let newDate = dateFormatter.stringFromDate(date)
    let diffDateComponent = NSCalendar.currentCalendar().components([NSCalendarUnit.Year, NSCalendarUnit.Month, NSCalendarUnit.Day], fromDate: latestDate, toDate: date, options: NSCalendarOptions.init(rawValue: 0))
    print(diffDateComponent.day)

但它只是检查两个 NSDate 是否相差 24 小时。我认为有一种方法可以让它工作，但我仍然希望在凌晨 2 点之前将 NSDate 值算作前一天，所以我在这里肯定需要一些帮助。谢谢！

Answer 1

NSCalendar 有一个方法可以完全按照您的实际需要进行操作！

/*
    This API compares the Days of the given dates, reporting them equal if they are in the same Day.
*/
- (BOOL)isDate:(NSDate *)date1 inSameDayAsDate:(NSDate *)date2 NS_AVAILABLE(10_9, 8_0);

所以你会这样使用它：

[[NSCalendar currentCalendar] isDate:date1 inSameDayAsDate:date2];

或者在 Swift 中

Calendar.current.isDate(date1, inSameDayAs:date2)

Answer 2

您应该比较日期组件：

let date1 = NSDate(timeIntervalSinceNow: 0)
let date2 = NSDate(timeIntervalSinceNow: 3600)

let components1 = NSCalendar.currentCalendar().components([.Year, .Month, .Day], fromDate: date1)
let components2 = NSCalendar.currentCalendar().components([.Year, .Month, .Day], fromDate: date2)

if components1.year == components2.year && components1.month == components2.month && components1.day == components2.day {
    print("same date")
} else {
    print("different date")
}

或更短：

let diff = Calendar.current.dateComponents([.day], from: self, to: date)
if diff.day == 0 {
    print("same day")
} else {
    print("different day")
}