Question

我想将nsdate转换为相对格式，如"Today","Yesterday","a week ago","a month ago","a year ago","date as it is"。

我已经为它编写了以下方法..但有些如何只是打印，因为它是日期..你能告诉我应该是什么问题吗？

//以下是我的函数，它将日期转换为相对字符串

+(NSString *)getDateDiffrence:(NSDate *)strDate{
    NSDateFormatter *df = [[NSDateFormatter alloc] init];

    df.timeStyle = NSDateFormatterMediumStyle;
    df.dateStyle = NSDateFormatterShortStyle;
    df.doesRelativeDateFormatting = YES;
    NSLog(@"STRING DATEEE : %@ REAL DATE TODAY %@",[df stringFromDate:strDate],[NSDate date]);
      return [df stringFromDate:strDate];

}

我的日期字符串格式为"2013-10-29T09:38:00"

当我试图给出NSDate对象时，它总是返回我的null日期所以我试图将该日期转换为yyyy-MM-dd HH:mm:ssZZZZ然后我将此日期传递给函数然后它只是打印整个日期..

如何解决这个问题？

//以下是我调用上述函数的代码

NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"yyyy-MM-dd'T'HH:mm:ss"];
NSDate *date = [formatter dateFromString:[threadDict objectForKey:@"lastMessageDate"]];
[formatter setDateFormat:@"yyyy-MM-dd HH:mm:ssZZZZ"];

NSString *date1 = [formatter stringFromDate:date];
NSDate *date_d = [formatter dateFromString:date1];
NSString *resultstr=[UserManager getDateDiffrence:date];

self.dateLabel.text=resultstr;

Answer 1

为简单起见，我假设你格式化的日期都是过去的（没有“明天”或“下周”）。并不是说它无法完成，而是处理更多的情况并返回更多的字符串。

您可以将components:fromDate:toDate:options:与您要查找的日期组件的任意组合一起使用，以获取两个日期之间的年，月，周，日，小时等。然后按照从最重要（例如年份）到最不重要（例如日）的顺序浏览它们，您可以仅根据最重要的组件格式化字符串。

例如：1周，2天和7小时前的日期格式为“1周”。

如果要为特定数量的单位创建特殊字符串，例如“明天”为“1天前”，则可以在确定该组件是最重要的组件后检查该组件的值。 / p>

代码看起来像这样：

- (NSString *)relativeDateStringForDate:(NSDate *)date
{
    NSCalendarUnit units = NSCalendarUnitDay | NSCalendarUnitWeekOfYear | 
                           NSCalendarUnitMonth | NSCalendarUnitYear;

    // if `date` is before "now" (i.e. in the past) then the components will be positive
    NSDateComponents *components = [[NSCalendar currentCalendar] components:units
                                                                   fromDate:date
                                                                     toDate:[NSDate date]
                                                                    options:0];

    if (components.year > 0) {
        return [NSString stringWithFormat:@"%ld years ago", (long)components.year];
    } else if (components.month > 0) {
        return [NSString stringWithFormat:@"%ld months ago", (long)components.month];
    } else if (components.weekOfYear > 0) {
        return [NSString stringWithFormat:@"%ld weeks ago", (long)components.weekOfYear];
    } else if (components.day > 0) {
        if (components.day > 1) {
            return [NSString stringWithFormat:@"%ld days ago", (long)components.day];
        } else {
            return @"Yesterday";
        }
    } else {
        return @"Today";
    }
}

如果您的日期也可能在将来，那么您可以按相同的顺序检查组件的绝对值，然后检查它是正还是负，以返回相应的字符串。我只展示下面的一年：

if ( abs(components.year > 0) ) { 
    // year is most significant component
    if (components.year > 0) {
        // in the past
        return [NSString stringWithFormat:@"%ld years ago", (long)components.year];
    } else {
        // in the future
        return [NSString stringWithFormat:@"In %ld years", (long)components.year];
    }
}

Answer 2

快速更新，感谢DavidRönnqvist的客观答案，它将适用于过去的日期。

func relativeDateStringForDate(date : NSDate) -> NSString {

        let todayDate = NSDate()
        let units: NSCalendarUnit = [.Hour, .Day, .Month, .Year, .WeekOfYear]
        let components = NSCalendar.currentCalendar().components(units, fromDate: date , toDate: todayDate, options: NSCalendarOptions.MatchFirst )

        let year =  components.year
        let month = components.month
        let day = components.day
        let hour = components.hour
        let weeks = components.weekOfYear
        // if `date` is before "now" (i.e. in the past) then the components will be positive

        if components.year > 0 {
            return NSString.init(format: "%d years ago", year);
        } else if components.month > 0 {
            return NSString.init(format: "%d months ago", month);
        } else if components.weekOfYear > 0 {
            return NSString.init(format: "%d weeks ago", weeks);
        } else if (components.day > 0) {
            if components.day > 1 {
                return NSString.init(format: "%d days ago", day);
            } else {
                return "Yesterday";
            }
        } else {
            return NSString.init(format: "%d hours ago", hour);
        }
    }

Answer 3

这是我的答案（在 Swift 3 中！）以及为什么它会更好。

答案：

func datePhraseRelativeToToday(from date: Date) -> String {

    // Don't use the current date/time. Use the end of the current day 
    // (technically 0h00 the next day). Apple's calculation of 
    // doesRelativeDateFormatting niavely depends on this start date.
    guard let todayEnd = dateEndOfToday() else {
        return ""
    }

    let calendar = Calendar.autoupdatingCurrent

    let units = Set([Calendar.Component.year,
                 Calendar.Component.month,
                 Calendar.Component.weekOfMonth,
                 Calendar.Component.day])

    let difference = calendar.dateComponents(units, from: date, to: todayEnd)

    guard let year = difference.year,
        let month = difference.month,
        let week = difference.weekOfMonth,
        let day = difference.day else {
            return ""
    }

    let timeAgo = NSLocalizedString("%@ ago", comment: "x days ago")

    let dateFormatter: DateFormatter = {
        let formatter = DateFormatter()
        formatter.locale = Locale.autoupdatingCurrent
        formatter.dateStyle = .medium
        formatter.doesRelativeDateFormatting = true
        return formatter
    }()

    if year > 0 {
        // sample output: "Jan 23, 2014"
        return dateFormatter.string(from: date)
    } else if month > 0 {
        let formatter = DateComponentsFormatter()
        formatter.unitsStyle = .brief // sample output: "1mth"
        formatter.allowedUnits = .month
        guard let timePhrase = formatter.string(from: difference) else {
            return ""
        }
        return String(format: timeAgo, timePhrase)
    } else if week > 0 {
        let formatter = DateComponentsFormatter()
        formatter.unitsStyle = .brief; // sample output: "2wks"
        formatter.allowedUnits = .weekOfMonth
        guard let timePhrase = formatter.string(from: difference) else {
            return ""
        }
        return String(format: timeAgo, timePhrase)
    } else if day > 1 {
            let formatter = DateComponentsFormatter()
            formatter.unitsStyle = .abbreviated; // sample output: "3d"
            formatter.allowedUnits = .day
            guard let timePhrase = formatter.string(from: difference) else {
                return ""
            }
            return String(format: timeAgo, timePhrase)
    } else {
        // sample output: "Yesterday" or "Today"
        return dateFormatter.string(from: date)
    }
}

func dateEndOfToday() -> Date? {
    let calendar = Calendar.autoupdatingCurrent
    let now = Date()
    let todayStart = calendar.startOfDay(for: now)
    var components = DateComponents()
    components.day = 1
    let todayEnd = calendar.date(byAdding: components, to: todayStart)
    return todayEnd
}

请记住 reuse your formatters以避免任何性能损失！提示：DateFormatter和DateComponentsFormatter上的扩展是好主意。

为什么它更好：

利用DateFormatter＆＃34;＆＃34;昨天＆＃34;和＆＃34;今天＆＃34;。这已经由Apple翻译，可以为您节省工作！
使用DateComponentsFormatter已翻译＆＃34; 1周＆＃34;串。（再次为你工作，Apple的礼貌。）你所要做的就是翻译＆＃34;％@ ago＆＃34;串。
其他答案错误地计算了当天从＆＃34;今天＆＃34;昨天＆＃34;昨天＆＃34;固定常数是一个很大的NO-NO，因为reasons。此外，其他答案使用当前日期/时间，他们应该使用结束当天日期/时间。
使用autoupdatingCurrent for Calendar＆amp;区域设置可确保您的应用在Settings.app中立即与用户的日历和语言首选项保持同步。

这个答案的灵感来自GitHub上的DateTools。

Answer 4

FOR：SWIFT 3

这是一个Swift 3版本，对于过去的日期，它处理返回的String中的所有单位和单数或复数。

使用示例：

let oneWeekAgo = Calendar.current.date(byAdding: .weekOfYear, value: -1, to: Date())!

print(relativePast(for: oneWeekAgo)) // output: "1 week ago"

我的基础是Saurabh Yadav's。感谢。

func relativePast(for date : Date) -> String {

    let units = Set<Calendar.Component>([.year, .month, .day, .hour, .minute, .second, .weekOfYear])
    let components = Calendar.current.dateComponents(units, from: date, to: Date())

    if components.year! > 0 {
        return "\(components.year!) " + (components.year! > 1 ? "years ago" : "year ago")

    } else if components.month! > 0 {
        return "\(components.month!) " + (components.month! > 1 ? "months ago" : "month ago")

    } else if components.weekOfYear! > 0 {
        return "\(components.weekOfYear!) " + (components.weekOfYear! > 1 ? "weeks ago" : "week ago")

    } else if (components.day! > 0) {
        return (components.day! > 1 ? "\(components.day!) days ago" : "Yesterday")

    } else if components.hour! > 0 {
        return "\(components.hour!) " + (components.hour! > 1 ? "hours ago" : "hour ago")

    } else if components.minute! > 0 {
        return "\(components.minute!) " + (components.minute! > 1 ? "minutes ago" : "minute ago")

    } else {
        return "\(components.second!) " + (components.second! > 1 ? "seconds ago" : "second ago")
    }
}

Answer 5

为了避免Budidino提到大卫答案的24小时问题，我将其改为如下所示 -

- (NSString *)relativeDateStringForDate:(NSDate *)date
{

NSCalendarUnit units = NSDayCalendarUnit | NSWeekOfYearCalendarUnit |
NSMonthCalendarUnit | NSYearCalendarUnit ;
NSCalendar *cal = [NSCalendar currentCalendar];
NSDateComponents *components1 = [cal components:(NSCalendarUnitEra|NSCalendarUnitYear|NSCalendarUnitMonth|NSCalendarUnitDay) fromDate:[NSDate date]];
NSDate *today = [cal dateFromComponents:components1];

components1 = [cal components:(NSCalendarUnitEra|NSCalendarUnitYear|NSCalendarUnitMonth|NSCalendarUnitDay) fromDate:date];
NSDate *thatdate = [cal dateFromComponents:components1];

// if `date` is before "now" (i.e. in the past) then the components will be positive
NSDateComponents *components = [[NSCalendar currentCalendar] components:units
                                                               fromDate:thatdate
                                                                 toDate:today
                                                                options:0];

if (components.year > 0) {
    return [NSString stringWithFormat:@"%ld years ago", (long)components.year];
} else if (components.month > 0) {
    return [NSString stringWithFormat:@"%ld months ago", (long)components.month];
} else if (components.weekOfYear > 0) {
    return [NSString stringWithFormat:@"%ld weeks ago", (long)components.weekOfYear];
} else if (components.day > 0) {
    if (components.day > 1) {
        return [NSString stringWithFormat:@"%ld days ago", (long)components.day];
    } else {
        return @"Yesterday";
    }
} else {
    return @"Today";
}
}

基本上，它会创建2个新的日期而不包含时间片。然后比较在＆＃34;天＆＃34;差。

Answer 6

检查NSDate-TimeAgo，它还支持多种语言。

Answer 7

你需要自己解决这个问题。您需要确定这两个日期之间的天数。

这是一种相对天真的方法：

+ (NSString *) dateDifference:(NSDate *)date
{
    const NSTimeInterval secondsPerDay = 60 * 60 * 24;
    NSTimeInterval diff = [date timeIntervalSinceNow] * -1.0;

    // if the difference is negative, then the given date/time is in the future
    // (because we multiplied by -1.0 to make it easier to follow later)
    if (diff < 0)
        return @"In the future";

    diff /= secondsPerDay; // get the number of days

    // if the difference is less than 1, the date occurred today, etc.
    if (diff < 1)
        return @"Today";
    else if (diff < 2)
        return @"Yesterday";
    else if (diff < 8)
        return @"Last week";
    else
        return [date description]; // use a date formatter if necessary
}

出于多种原因这是天真的：

没有考虑闰日
假设一天有86400秒（有闰秒这样的东西！）

然而，这至少应该帮助你朝着正确的方向前进。另外，请避免在方法名称中使用get。在方法名称中使用get通常表示调用者必须提供自己的输出缓冲区。考虑NSArray的方法，getItems:range:和NSString的方法getCharacters:range:。

Answer 8

NSString* AgoStringFromTime(NSDate* dateTime)
{
    NSDictionary *timeScale = @{@"sec"  :@1,
                                @"min"  :@60,
                                @"hr"   :@3600,
                                @"day"  :@86400,
                                @"week" :@605800,
                                @"month":@2629743,
                                @"year" :@31556926};
    NSString *scale;
    int timeAgo = 0-(int)[dateTime timeIntervalSinceNow];
    if (timeAgo < 60) {
        scale = @"sec";
    } else if (timeAgo < 3600) {
        scale = @"min";
    } else if (timeAgo < 86400) {
        scale = @"hr";
    } else if (timeAgo < 605800) {
        scale = @"day";
    } else if (timeAgo < 2629743) {
        scale = @"week";
    } else if (timeAgo < 31556926) {
        scale = @"month";
    } else {
        scale = @"year";
    }

    timeAgo = timeAgo/[[timeScale objectForKey:scale] integerValue];
    NSString *s = @"";
    if (timeAgo > 1) {
        s = @"s";
    }

    return [NSString stringWithFormat:@"%d %@%@", timeAgo, scale, s];
}

Answer 9

以下是我为使用而创建的代码：

+ (NSString*) getTimestampForDate:(NSDate*)date {

    NSDate* sourceDate = date;

    // Timezone Offset compensation (optional, if your target users are limited to a single time zone.)

    NSTimeZone* sourceTimeZone = [NSTimeZone timeZoneWithName:@"America/New_York"];
    NSTimeZone* destinationTimeZone = [NSTimeZone systemTimeZone];

    NSInteger sourceGMTOffset = [sourceTimeZone secondsFromGMTForDate:sourceDate];
    NSInteger destinationGMTOffset = [destinationTimeZone secondsFromGMTForDate:sourceDate];

    NSTimeInterval interval = destinationGMTOffset - sourceGMTOffset;

    NSDate* destinationDate = [[NSDate alloc] initWithTimeInterval:interval sinceDate:sourceDate];

    // Timestamp calculation (based on compensation)

    NSCalendar* currentCalendar = [NSCalendar currentCalendar];
    NSCalendarUnit unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit |  NSDayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit;

    NSDateComponents *differenceComponents = [currentCalendar components:unitFlags fromDate:destinationDate toDate:[NSDate date] options:0];//Use `date` instead of `destinationDate` if you are not using Timezone offset correction

    NSInteger yearDifference = [differenceComponents year];
    NSInteger monthDifference = [differenceComponents month];
    NSInteger dayDifference = [differenceComponents day];
    NSInteger hourDifference = [differenceComponents hour];
    NSInteger minuteDifference = [differenceComponents minute];

    NSString* timestamp;

    if (yearDifference == 0
        && monthDifference == 0
        && dayDifference == 0
        && hourDifference == 0
        && minuteDifference <= 2) {

        //"Just Now"

        timestamp = @"Just Now";

    } else if (yearDifference == 0
               && monthDifference == 0
               && dayDifference == 0
               && hourDifference == 0
               && minuteDifference < 60) {

        //"13 minutes ago"

        timestamp = [NSString stringWithFormat:@"%ld minutes ago", (long)minuteDifference];

    } else if (yearDifference == 0
               && monthDifference == 0
               && dayDifference == 0
               && hourDifference == 1) {

        //"1 hour ago" EXACT

        timestamp = @"1 hour ago";

    } else if (yearDifference == 0
               && monthDifference == 0
               && dayDifference == 0
               && hourDifference < 24) {

        timestamp = [NSString stringWithFormat:@"%ld hours ago", (long)hourDifference];

    } else {

        NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
        [formatter setLocale:[NSLocale currentLocale]];

        NSString* strDate, *strDate2 = @"";

        if (yearDifference == 0
            && monthDifference == 0
            && dayDifference == 1) {

            //"Yesterday at 10:23 AM", "Yesterday at 5:08 PM"

            [formatter setDateFormat:@"hh:mm a"];
            strDate = [formatter stringFromDate:date];

            timestamp = [NSString stringWithFormat:@"Yesterday at %@", strDate];

        } else if (yearDifference == 0
                   && monthDifference == 0
                   && dayDifference < 7) {

            //"Tuesday at 7:13 PM"

            [formatter setDateFormat:@"EEEE"];
            strDate = [formatter stringFromDate:date];
            [formatter setDateFormat:@"hh:mm a"];
            strDate2 = [formatter stringFromDate:date];

            timestamp = [NSString stringWithFormat:@"%@ at %@", strDate, strDate2];

        } else if (yearDifference == 0) {

            //"July 4 at 7:36 AM"

            [formatter setDateFormat:@"MMMM d"];
            strDate = [formatter stringFromDate:date];
            [formatter setDateFormat:@"hh:mm a"];
            strDate2 = [formatter stringFromDate:date];

            timestamp = [NSString stringWithFormat:@"%@ at %@", strDate, strDate2];

        } else {

            //"March 24 2010 at 4:50 AM"

            [formatter setDateFormat:@"d MMMM yyyy"];
            strDate = [formatter stringFromDate:date];
            [formatter setDateFormat:@"hh:mm a"];
            strDate2 = [formatter stringFromDate:date];

            timestamp = [NSString stringWithFormat:@"%@ at %@", strDate, strDate2];
        }
    }

    return timestamp;
}

Answer 10

这只是上一个答案的副本，但如果小于5秒，则返回Just now。

func relativePast(for date : Date) -> String {

    let units = Set<Calendar.Component>([.year, .month, .day, .hour, .minute, .second, .weekOfYear])
    let components = Calendar.current.dateComponents(units, from: date, to: Date())

    if components.year! > 0 {
        return "\(components.year!) " + (components.year! > 1 ? "years ago" : "year ago")

    } else if components.month! > 0 {
        return "\(components.month!) " + (components.month! > 1 ? "months ago" : "month ago")

    } else if components.weekOfYear! > 0 {
        return "\(components.weekOfYear!) " + (components.weekOfYear! > 1 ? "weeks ago" : "week ago")

    } else if (components.day! > 0) {
        return (components.day! > 1 ? "\(components.day!) days ago" : "Yesterday")

    } else if components.hour! > 0 {
        return "\(components.hour!) " + (components.hour! > 1 ? "hours ago" : "hour ago")

    } else if components.minute! > 0 {
        return "\(components.minute!) " + (components.minute! > 1 ? "minutes ago" : "minute ago")

    } else {
        return "\(components.second!) " + (components.second! > 5 ? "seconds ago" : "Just Now".replacingOccurrences(of: "0", with: "")
    }
}

Answer 11

doesRelativeDateFormatting的问题在于它几乎仅限于Yesterday，Today，Tomorrow。如果您正在寻找更全面的内容，请查看the answers here。

Answer 12

比较代码如果期货日期

NSCalendarUnit units = NSCalendarUnitDay | NSCalendarUnitWeekOfYear | 
                           NSCalendarUnitMonth | NSCalendarUnitYear;


    NSDateComponents *components = [[NSCalendar currentCalendar] components:units fromDate:date toDate:[NSDate date] options:0];

    if (components.year < 0) {
            return [NSString stringWithFormat:@"%ld years from now", labs((long)components.year)];
        } else if (components.month < 0) {
            return [NSString stringWithFormat:@"%ld months from now", labs((long)components.month)];
        } else if (components.weekOfYear < 0) {
            return [NSString stringWithFormat:@"%ld weeks from now", labs((long)components.weekOfYear)];
        } else if (components.day < 0) {
            if (components.day < 1) {
                return [NSString stringWithFormat:@"%ld days from now", labs((long)components.day)];
            } else {
                return @"Tomorrow";
            }
        }
        else if (components.year > 0) {
            return [NSString stringWithFormat:@"%ld years ago", (long)components.year];
        } else if (components.month > 0) {
            return [NSString stringWithFormat:@"%ld months ago", (long)components.month];
        } else if (components.weekOfYear > 0) {
            return [NSString stringWithFormat:@"%ld weeks ago", (long)components.weekOfYear];
        } else if (components.day > 0) {
            if (components.day > 1) {
                return [NSString stringWithFormat:@"%ld days ago", (long)components.day];
            } else {
                return @"Yesterday";
            }
        } else {
            return @"Today";
        }

Answer 13

我在这里附带演示，请在此链接上找到。 TimestampAgo-Demo

感谢n00bprogrammer

编辑： - 我使用[NSTimeZone systemTimeZone]在Sourcetimezone中进行了更改，因为由于静态时区，以GMT或UTC格式发生问题。（第二个是减号）并更改已弃用的方法。

Answer 14

这是我在Swift 2中的解决方案，通过将两个日期与零时间进行比较来避免24小时问题。

extension NSDate {

private func dateWithZeroTime(date: NSDate) -> NSDate? {
    let calendar = NSCalendar.currentCalendar()
    let units: NSCalendarUnit = [.Day, .WeekOfYear, .Month, .Year]
    let components = calendar.components(units, fromDate: date)
    return calendar.dateFromComponents(components)
}

private func thisDay() -> NSDate? {
    return self.dateWithZeroTime(self)
}

private func today() -> NSDate? {
    return self.dateWithZeroTime(NSDate())
}

var relativeFormat: String? {
    let today = self.today()
    let thisDay = self.thisDay()

    let formatter = NSDateFormatter()
    formatter.dateStyle = NSDateFormatterStyle.LongStyle
    let dateString = formatter.stringFromDate(self)

    if nil != thisDay && nil != today {
        let units: NSCalendarUnit = [.Day, .WeekOfYear, .Month, .Year]
        let components = NSCalendar.currentCalendar().components(units, fromDate: thisDay!, toDate: today!, options: [])

        if (components.year > 0) {
            return components.year == 1 ? "A year ago, \(dateString)" : "\(components.year) years ago, \(dateString)"
        } else if (components.month > 0) {
            return components.month == 1 ? "A month ago, \(dateString)" : "\(components.month) months ago, \(dateString)"
        } else if (components.weekOfYear > 0) {
            return components.weekOfYear == 1 ? "A week ago, \(dateString)" : "\(components.weekOfYear) weeks ago, \(dateString)"
        } else if (components.day > 0) {
            return components.day == 1 ? "Yesterday, \(dateString)" : "\(self.dayOfTheWeek()), \(dateString)"
        } else {
            return "Today"
        }
    }

    return nil
}

func dayOfTheWeek() -> String {
    let weekdays = [
        "Sunday",
        "Monday",
        "Tuesday",
        "Wednesday",
        "Thursday",
        "Friday",
        "Saturday"
    ]

    let calendar: NSCalendar = NSCalendar.currentCalendar()
    let components: NSDateComponents = calendar.components(.Weekday, fromDate: self)
    return weekdays[components.weekday - 1]
}
}

Answer 15

格式化给定的＆＃34; sourceDate＆＃34; as＆＃34; 5:56 pm＆＃34;今天，＆＃34;昨天＆＃34;昨天任何时候，＆＃34; 1月16日＆＃34;在同一年的任何一天和＃34; 2014年1月16日＆＃34;。我发布了自己的方法。

sourceDate = //some date that you need to take into consideration


 NSDateComponents *components = [[NSCalendar currentCalendar] components:NSCalendarUnitMinute | NSCalendarUnitHour | NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear fromDate:[NSDate date]];
    NSDateComponents *sourceDateComponents = [[NSCalendar currentCalendar] components:NSCalendarUnitMinute | NSCalendarUnitHour | NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear fromDate: sourceDate];

    NSString* timestamp;

    NSDateFormatter *formatSourceDate   =   [NSDateFormatter new];
    [formatSourceDate setAMSymbol:@"AM"];
    [formatSourceDate setPMSymbol:@"PM"];

    //same day - time in h:mm am/pm
    if (components.day == sourceDateComponents.day) {
        NSLogInfo(@"time");
        [formatSourceDate setDateFormat:@"h:mm a"];
        timestamp = [NSString stringWithFormat:@"%@",[formatSourceDate stringFromDate:date]];
        return timestamp;
    }
    else if (components.day - sourceDateComponents.day == 1) {
        //yesterday
        timestamp = NSLocalizedString(@"Yesterday", nil);
        return timestamp;
    }
    if (components.year == sourceDateComponents.year) {
        //september 29, 5:56 pm
        [formatSourceDate setDateFormat:@"MMMM d"];
        timestamp = [NSString stringWithFormat:@"%@",[formatSourceDate stringFromDate:date]];
        return timestamp;
    }
    [formatSourceDate setDateFormat:@"MMMM d year"];
    timestamp = [NSString stringWithFormat:@"%@",[formatSourceDate stringFromDate:date]];
    return timestamp;

    NSLogInfo(@"Timestamp : %@",timestamp);

Answer 16

let formatter = DateComponentsFormatter()
formatter.unitsStyle = .full

let now = NSDate()


let dateMakerFormatter = DateFormatter()

dateMakerFormatter.dateFormat = "yyyy/MM/dd HH:mm:ss z"
let dateString = "2017-03-13 10:38:54 +0000"
let stPatricksDay = dateMakerFormatter.date(from: dateString)!


let calendar = NSCalendar.current



let components = calendar.dateComponents([.hour, .minute,.weekOfMonth,.day,.year,.month,.second], from: stPatricksDay, to: now as Date)



if components.year! > 0 {
    formatter.allowedUnits = .year
} else if components.month! > 0 {
    formatter.allowedUnits = .month
} else if components.weekOfMonth! > 0 {
    formatter.allowedUnits = .weekOfMonth
} else if components.day! > 0 {
    formatter.allowedUnits = .day
} else if components.hour! > 0 {
    formatter.allowedUnits = .hour
} else if components.minute! > 0 {
    formatter.allowedUnits = .minute
} else {
    formatter.allowedUnits = .second
}

let formatString = NSLocalizedString("%@ ago", comment: "Used to say how much time has passed. e.g. '2 hours ago'")

 let timeString = formatter.string(from: components)

String(format: formatString, timeString!)

如何将NSDate转换为相对格式为“今天”，“昨天”，“一周前”，“一个月前”，“一年前”？

16 个答案:

答案：

为什么它更好：