如何从 "Tonight at 7PM" 中获取 NSDate？

Question

我有几个表示 "Tonight at 8PM" 或 "Tonight at 6PM" 的字符串，我需要找出如何将它们转换为 NSDates。我需要格式为 yyyy/mm/dd/hh.

更新：

现在我返回了错误的年份。我得到 9223372036854775807 年。

let calendar = NSCalendar.currentCalendar()
let components = calendar.components([.Month, .Day, .Year], fromDate:NSDate())
let year =  components.year
let month = components.month
let day = components.day

let NSDateString = "\(month)/\(day)/\(year) at \(date.chopPrefix(11))"
print(NSDateString)

Answer 1

我现在的工作如下：

let inputString = "Tonight at 6PM"

let calendar = NSCalendar.currentCalendar()
let components = calendar.components([.Year, .Month, .Day], fromDate: NSDate())

let dfm = NSDateFormatter()
dfm.dateFormat = "'Tonight at' hha"

let inputDate = dfm.dateFromString(inputString)!
let hour = calendar.components(.Hour, fromDate: inputDate).hour

let outputDate = calendar.dateFromComponents(components)?.dateByAddingTimeInterval(Double(hour * 60 * 60))

输出：

Oct 4, 2015, 6:00 PM

一种不同的方法是将今天的日期附加到输入字符串，然后再次一起解析。

Answer 2

您不需要自己进行解析。有方便的 NSDataDetector class 可以为您完成此操作：

let string = "Tonight at 7pm"

// Create an NSDataDetector that looks for dates
let detector = try! NSDataDetector(types: NSTextCheckingType.Date.rawValue)

// Create an array of all the possible matches
let matches = detector.matchesInString(string, options: [], range: NSMakeRange(0, string.utf16.count))

// Since you are only expecting one date, extract it.
if let date = matches.first?.date  {
    print("\(date)")
} else {
    print("No matches found")
}

这会为您处理区域设置。例如 - 我所在的位置给出了结果日期：

"2015-10-04 18:00:00 +0000"

这为您提供了一个很好的原始 NSDate 实例，您可以根据需要存储或提供格式化输出。

此外，这不会将您局限于 "today"。将此代码放在操场上并尝试以下操作：

let string = "Wednesday at 7pm"

或

let string = "Yesterday at 7pm"

或

let string = "tomorrow morning at 2"

其中所有 return 个有效日期。

如何从 "Tonight at 7PM" 中获取 NSDate？

How can I get an NSDate out of "Tonight at 7PM"?

swift

nsdate

ios9