我有一个
TimeInterval
,我必须将它变成 String
,以便可以将其添加到通过 Dictionary
从 Apple Watch 传递到 iPhone 的 WatchConnectivity
。
现在我在 iPhone 上有了
String
,我需要将其变回 TimeInterval
,但我似乎无法弄清楚。
(我需要在
UILabel
中显示此内容,以显示锻炼课程的持续时间。)
有什么想法吗?
例如
观看:
00:15:15(时、分、秒)变成“915.012948989868”
let myDouble = computeDurationOfWorkout(withEvents: hkWorkout?.workoutEvents, startDate: hkWorkout?.startDate, endDate: hkWorkout?.endDate)
let myDoubleString = String(myDouble)
durationVariableString = myDoubleString
iPhone:
需要将“915.012948989868”改回00:15:15
使用
calendar.dateComponents
您可以将 915
转换为 00:15:15
func stringFromTimeInterval (interval: String) -> String {
let endingDate = Date()
if let timeInterval = TimeInterval(interval) {
let startingDate = endingDate.addingTimeInterval(-timeInterval)
let calendar = Calendar.current
var componentsNow = calendar.dateComponents([.hour, .minute, .second], from: startingDate, to: endingDate)
if let hour = componentsNow.hour, let minute = componentsNow.minute, let seconds = componentsNow.second {
return "\(hour):\(minute):\(seconds)"
} else {
return "00:00:00"
}
} else {
return "00:00:00"
}
}
这可以作为 TimeInterval 的扩展来完成。此版本还可以正确处理分钟/秒< 10 by padding them.
extension TimeInterval {
var formatted: String {
let endingDate = Date()
let startingDate = endingDate.addingTimeInterval(-self)
let calendar = Calendar.current
var componentsNow = calendar.dateComponents([.hour, .minute, .second], from: startingDate, to: endingDate)
if let hour = componentsNow.hour, let minute = componentsNow.minute, let seconds = componentsNow.second {
return "\(String(format: "%02d", hour)):\(String(format: "%02d", minute)):\(String(format: "%02d", seconds))"
} else {
return "00:00:00"
}
}
}
并内联处理 String -> TimeInterval 转换。
TimeInterval(intervalAsString).formatted
不要将时间间隔变成字符串,而是将其变成可以添加到字典中的 NSNumber。 NSTimeInterval 只是一个双精度数,因此您可以轻松地将其转换为双精度数或从双精度数转换。
let timeInterval: TimeInterval = 915.012948989868
let dict = ["TimeIneterval": NSNumber(value: timeInterval)]
if let extractedTimeInterval: TimeInterval = dict["TimeIneterval"] as? TimeInterval {
print(extractedTimeInterval)
}
找到了原生的简单解决方案
DateComponentsFormatter
:
func formatted(interval: TimeInterval) -> String {
let formatter = DateComponentsFormatter()
formatter.allowedUnits = [.hour, .minute, .second]
formatter.zeroFormattingBehavior = .dropLeading // drop leading zero values
return formatter.string(from: timeInterval)
}