Ale*_*ler 53 iphone cocoa objective-c
比如我有
NSDate *curDate = [NSDate date];
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它的价值是上午9:13.我没有使用curDate的年,月和日部分.
我想得到的是9:15时间值的日期; 如果我有时间价值9:16我想把它推进到9:20,依此类推.
我怎么能用NSDate做到这一点?
mkk*_*kko 56
这是我的解决方案:
NSTimeInterval seconds = round([date timeIntervalSinceReferenceDate]/300.0)*300.0;
NSDate *rounded = [NSDate dateWithTimeIntervalSinceReferenceDate:seconds];
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我做了一些测试,它的速度是Voss解决方案的十倍.通过1M迭代,大约需要3.39秒.这一次在0.38秒内完成.J3RM的解决方案耗时0.50秒.内存使用量也应该是最低的.
并不是表现就是一切,但它是一个单行.您还可以使用除法和乘法轻松控制舍入.
编辑:要回答这个问题,您可以使用ceil正确的向上舍入:
NSTimeInterval seconds = ceil([date timeIntervalSinceReferenceDate]/300.0)*300.0;
NSDate *rounded = [NSDate dateWithTimeIntervalSinceReferenceDate:seconds];
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编辑:Swift中的扩展:
public extension Date {
public func round(precision: TimeInterval) -> Date {
return round(precision: precision, rule: .toNearestOrAwayFromZero)
}
public func ceil(precision: TimeInterval) -> Date {
return round(precision: precision, rule: .up)
}
public func floor(precision: TimeInterval) -> Date {
return round(precision: precision, rule: .down)
}
private func round(precision: TimeInterval, rule: FloatingPointRoundingRule) -> Date {
let seconds = (self.timeIntervalSinceReferenceDate / precision).rounded(rule) * precision;
return Date(timeIntervalSinceReferenceDate: seconds)
}
}
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Dus*_*oss 54
取分钟值,除以5向上舍入以获得下一个最高的5分钟单位,乘以5以便在几分钟内将其重新计算,并构建一个新的NSDate.
NSDateComponents *time = [[NSCalendar currentCalendar]
components:NSHourCalendarUnit | NSMinuteCalendarUnit
fromDate:curDate];
NSInteger minutes = [time minute];
float minuteUnit = ceil((float) minutes / 5.0);
minutes = minuteUnit * 5.0;
[time setMinute: minutes];
curDate = [[NSCalendar currentCalendar] dateFromComponents:time];
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Gre*_*egP 27
基于Chris'和swift3这个怎么样?
import UIKit
enum DateRoundingType {
case round
case ceil
case floor
}
extension Date {
func rounded(minutes: TimeInterval, rounding: DateRoundingType = .round) -> Date {
return rounded(seconds: minutes * 60, rounding: rounding)
}
func rounded(seconds: TimeInterval, rounding: DateRoundingType = .round) -> Date {
var roundedInterval: TimeInterval = 0
switch rounding {
case .round:
roundedInterval = (timeIntervalSinceReferenceDate / seconds).rounded() * seconds
case .ceil:
roundedInterval = ceil(timeIntervalSinceReferenceDate / seconds) * seconds
case .floor:
roundedInterval = floor(timeIntervalSinceReferenceDate / seconds) * seconds
}
return Date(timeIntervalSinceReferenceDate: roundedInterval)
}
}
// Example
let nextFiveMinuteIntervalDate = Date().rounded(minutes: 5, rounding: .ceil)
print(nextFiveMinuteIntervalDate)
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BJ *_*ler 27
Wowsers,我在这里看到了很多答案,但很多很长或很难理解,所以我会尝试投入2美分以防万一.该NSCalendar课程以安全和简洁的方式提供所需的功能.这是一个适合我的解决方案,没有乘以时间间隔秒,舍入或任何东西.NSCalendar考虑到闰日/年,以及其他时间和日期的怪异.(斯威夫特2.2)
let calendar = NSCalendar.currentCalendar()
let rightNow = NSDate()
let interval = 15
let nextDiff = interval - calendar.component(.Minute, fromDate: rightNow) % interval
let nextDate = calendar.dateByAddingUnit(.Minute, value: nextDiff, toDate: rightNow, options: []) ?? NSDate()
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NSDate如果需要,可以将其添加到扩展中,或者作为返回新NSDate实例的自由格式函数,无论您需要什么.希望这可以帮助任何需要它的人.
Swift 3更新
let calendar = Calendar.current
let rightNow = Date()
let interval = 15
let nextDiff = interval - calendar.component(.minute, from: rightNow) % interval
let nextDate = calendar.date(byAdding: .minute, value: nextDiff, to: rightNow) ?? Date()
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J3R*_*3RM 13
我认为这是最好的解决方案,但仅限于我的观点,基于之前的海报代码.轮到最近的5分钟标记.此代码应使用比日期组件解决方案少得多的内存.太棒了,谢谢你的指导.
+(NSDate *) dateRoundedDownTo5Minutes:(NSDate *)dt{
int referenceTimeInterval = (int)[dt timeIntervalSinceReferenceDate];
int remainingSeconds = referenceTimeInterval % 300;
int timeRoundedTo5Minutes = referenceTimeInterval - remainingSeconds;
if(remainingSeconds>150)
{/// round up
timeRoundedTo5Minutes = referenceTimeInterval +(300-remainingSeconds);
}
NSDate *roundedDate = [NSDate dateWithTimeIntervalSinceReferenceDate:(NSTimeInterval)timeRoundedTo5Minutes];
return roundedDate;
}
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小智 7
https://forums.developer.apple.com/thread/92399
请参阅链接以获取Apple员工的完整和详细答案。为了节省您的时间,解决方案:
let original = Date()
let rounded = Date(timeIntervalSinceReferenceDate:
(original.timeIntervalSinceReferenceDate / 300.0).rounded(.toNearestOrEven) * 300.0)
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小智 6
谢谢你的样品.下面我添加了一些代码到最接近的5分钟
-(NSDate *)roundDateTo5Minutes:(NSDate *)mydate{
// Get the nearest 5 minute block
NSDateComponents *time = [[NSCalendar currentCalendar]
components:NSHourCalendarUnit | NSMinuteCalendarUnit
fromDate:mydate];
NSInteger minutes = [time minute];
int remain = minutes % 5;
// if less then 3 then round down
if (remain<3){
// Subtract the remainder of time to the date to round it down evenly
mydate = [mydate addTimeInterval:-60*(remain)];
}else{
// Add the remainder of time to the date to round it up evenly
mydate = [mydate addTimeInterval:60*(5-remain)];
}
return mydate;
}
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遗憾的是,这里的大多数回复都不完全正确(即使它们似乎对大多数用户来说效果都很好),因为它们要么依赖当前的活动系统日历作为公历(可能不是这种情况),要么依赖于OS X和iOS不会存在闰秒和/或总是会忽略闰秒.以下代码工作复制和粘贴,保证是正确的,并且没有做出这样的假设(因此,如果Apple改变闰秒支持,将来也不会破坏,因为在这种情况下NSCalendar也必须正确地支持它们):
{
NSDate * date;
NSUInteger units;
NSCalendar * cal;
NSInteger minutes;
NSDateComponents * comp;
// Get current date
date = [NSDate date];
// Don't rely that `currentCalendar` is a
// Gregorian calendar that works the way we are used to.
cal = [[NSCalendar alloc]
initWithCalendarIdentifier:NSGregorianCalendar
];
[cal autorelease]; // Delete that line if using ARC
// Units for the day
units = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit;
// Units for the time (seconds are irrelevant)
units |= NSHourCalendarUnit | NSMinuteCalendarUnit;
// Split current date into components
comp = [cal components:units fromDate:date];
// Get the minutes,
// will be a number between 0 and 59.
minutes = [comp minute];
// Unless it is a multiple of 5...
if (minutes % 5) {
// ... round up to the nearest multiple of 5.
minutes = ((minutes / 5) + 1) * 5;
}
// Set minutes again.
// Minutes may now be a value between 0 and 60,
// but don't worry, NSCalendar knows how to treat overflows!
[comp setMinute:minutes];
// Convert back to date
date = [cal dateFromComponents:comp];
}
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如果当前时间已经是5分钟的倍数,则代码不会更改它.原始问题没有明确指出这个案例.如果代码总是向上舍入到下一个5分钟的倍数,只需删除测试if (minutes % 5) {,它将始终向上舍入.
@ipje的答案在接下来的 5 分钟内发挥了作用,但我需要更灵活的东西,并且我想摆脱所有神奇的数字。我找到了一个解决方案,感谢类似问题的答案
我的解决方案使用 Swift 5.2 并Measurement避免使用幻数:
extension UnitDuration {
var upperUnit: Calendar.Component? {
if self == .nanoseconds {
return .second
}
if self == .seconds {
return .minute
}
if self == .minutes {
return .hour
}
if self == .hours {
return .day
}
return nil
}
}
extension Date {
func roundDate(to value: Int, in unit: UnitDuration, using rule: FloatingPointRoundingRule, and calendar: Calendar = Calendar.current) -> Date? {
guard unit != .picoseconds && unit != .nanoseconds,
let upperUnit = unit.upperUnit else { return nil }
let value = Double(value)
let unitMeasurement = Measurement(value: value, unit: unit)
let interval = unitMeasurement.converted(to: .seconds).value
let startOfPeriod = calendar.dateInterval(of: upperUnit, for: self)!.start
var seconds = self.timeIntervalSince(startOfPeriod)
seconds = (seconds / interval).rounded(rule) * interval
return startOfPeriod.addingTimeInterval(seconds)
}
func roundDate(toNearest value: Int, in unit: UnitDuration, using calendar: Calendar = Calendar.current) -> Date? {
return roundDate(to: value, in: unit, using: .toNearestOrEven)
}
func roundDate(toNext value: Int, in unit: UnitDuration, using calendar: Calendar = Calendar.current) -> Date? {
return roundDate(to: value, in: unit, using: .up)
}
}
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在我的操场上:
let calendar = Calendar.current
let date = Calendar.current.date(from: DateComponents(timeZone: TimeZone.current, year: 2020, month: 6, day: 12, hour: 00, minute: 24, second: 17, nanosecond: 577881))! // 12 Jun 2020 at 00:24
var roundedDate = date.roundDate(toNext: 5, in: .seconds)!
//"12 Jun 2020 at 00:24"
calendar.dateComponents([.nanosecond, .second, .minute, .hour, .day, .month], from: roundedDate)
// month: 6 day: 12 hour: 0 minute: 24 second: 20 nanosecond: 0 isLeapMonth: false
roundedDate = date.roundDate(toNearest: 5, in: .seconds)!
// "12 Jun 2020 at 00:24"
calendar.dateComponents([.nanosecond, .second, .minute, .hour, .day, .month], from: roundedDate)
// month: 6 day: 12 hour: 0 minute: 24 second: 15 nanosecond: 0 isLeapMonth: false
roundedDate = date.roundDate(toNext: 5, in: .minutes)!
// "12 Jun 2020 at 00:25"
calendar.dateComponents([.nanosecond, .second, .minute, .hour, .day, .month], from: roundedDate)
// month: 6 day: 12 hour: 0 minute: 25 second: 0 nanosecond: 0 isLeapMonth: false
roundedDate = date.roundDate(toNearest: 5, in: .minutes)!
// "12 Jun 2020 at 00:25"
calendar.dateComponents([.nanosecond, .second, .minute, .hour, .day, .month], from: roundedDate)
// month: 6 day: 12 hour: 0 minute: 25 second: 0 nanosecond: 0 isLeapMonth: false
roundedDate = date.roundDate(toNext: 5, in: .hours)!
// "12 Jun 2020 at 05:00"
calendar.dateComponents([.nanosecond, .second, .minute, .hour, .day, .month], from: roundedDate)
// month: 6 day: 12 hour: 5 minute: 0 second: 0 nanosecond: 0 isLeapMonth: false
roundedDate = date.roundDate(toNearest: 5, in: .hours)!
// "12 Jun 2020 at 00:00"
calendar.dateComponents([.nanosecond, .second, .minute, .hour, .day, .month], from: roundedDate)
// month: 6 day: 12 hour: 0 minute: 0 second: 0 nanosecond: 0 isLeapMonth: false
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