问题
I am using the following DateComponentsFormatter in Swift:
let formatter = DateComponentsFormatter()
formatter.unitsStyle = .positional
formatter.allowedUnits = [.hour, .minute, .second]
formatter.zeroFormattingBehavior = [.default]
This produces results like 2:41 (for 2 minutes and 41 seconds) and 08 (for 8 seconds). I would, however, like to keep at least one digit in the Minutes place, returning 0:08 instead of 08. Is this possible with the DateComponentsFormatter? I would prefer a solution that returns a localized result.
回答1:
Yes. This can be easily accomplished adding a ternary conditional based on the time interval when setting the date components formatter allowed units:
Xcode 11 • Swift 5.1
extension Formatter {
static let positional: DateComponentsFormatter = {
let positional = DateComponentsFormatter()
positional.unitsStyle = .positional
positional.zeroFormattingBehavior = .pad
return positional
}()
}
extension TimeInterval {
var positionalTime: String {
Formatter.positional.allowedUnits = self >= 3600 ?
[.hour, .minute, .second] :
[.minute, .second]
let string = Formatter.positional.string(from: self)!
return string.hasPrefix("0") && string.count > 4 ?
.init(string.dropFirst()) : string
}
}
Usage
8.0.positionalTime // "0:08"
161.0.positionalTime // "2:41"
3600.0.positionalTime // "1:00:00"
回答2:
Check out a different zeroFormattingBehavior property value. I use this to get the result I think you're seeking, but experiment as necessary...
formatter.zeroFormattingBehavior = [.pad]
来源:https://stackoverflow.com/questions/54641424/swift-datecomponentsformatter-drop-leading-zeroes-but-keep-at-least-one-digit-in