ios - NSDateFormatter dateFormatFromTemplate 问题

Question

我需要取回小时和分钟的本地化格式。时间按预期工作，但分钟返回“m”？为什么不返回“mm”？

let locale = NSDateFormatter().locale

NSDateFormatter.dateFormatFromTemplate("HH", options: 0, locale:locale)
//Returns "HH" in US English and "H时" in Chinese (Simplified)

NSDateFormatter.dateFormatFromTemplate("mm", options: 0, locale:locale)
//Returns "m" for both???

Answer 1

您是否尝试过使用 NSDateComponents ？

let date: NSDate = NSDate()
let calendar = NSCalendar.currentCalendar()

let components = calendar.components(NSCalendarUnit.CalendarUnitDay | NSCalendarUnit.CalendarUnitYear | NSCalendarUnit.CalendarUnitMonth | NSCalendarUnit.CalendarUnitHour | NSCalendarUnit.CalendarUnitMinute, fromDate: date)

components.hour = 20
components.minute = 10

if let newDate = calendar.dateFromComponents(components) {
    let dateFormatter = NSDateFormatter()
    dateFormatter.timeStyle = NSDateFormatterStyle.ShortStyle
    dateFormatter.stringFromDate(newDate)
}

这里再次作为检索所需值的函数:

func formattedTimeString(unitToSet: NSCalendarUnit, selectedValue: Int, template: String) -> String?
{
    let date: NSDate = NSDate()
    let calendar = NSCalendar.currentCalendar()

    let components = calendar.components(NSCalendarUnit.CalendarUnitDay | NSCalendarUnit.CalendarUnitYear | NSCalendarUnit.CalendarUnitMonth | NSCalendarUnit.CalendarUnitHour | NSCalendarUnit.CalendarUnitMinute, fromDate: date)

    if unitToSet == .CalendarUnitHour
    {
        components.hour = selectedValue
    } else
    {
        components.minute = selectedValue
    }

    if let newDate = calendar.dateFromComponents(components) {
        let dateFormatter = NSDateFormatter()

        dateFormatter.dateFormat = NSDateFormatter.dateFormatFromTemplate(template, options: 0, locale: NSLocale.currentLocale())

        return dateFormatter.stringFromDate(newDate)
    }

    return nil
}

if let hours: String = formattedTimeString(.CalendarUnitHour, 22, "HH")
{
    println(hours) // prints 22
}

if let minutes: String = formattedTimeString(.CalendarUnitMinute, 33, "mm")
{
    println(minutes) // prints 33
}

也可用 Gist ，如果您还有其他问题。