Question

我打算调用一个函数来检查从日期开始经过的时间。这将确定timeLable在我的消息视图控制器中的显示方式，类似于IMessage。

我在下面使用的代码只显示HH：MM

let date = dateFormatter().dateFromString((recent["date"] as? String)!)

timeLabel.text = NSDateFormatter.localizedStringFromDate(date!, dateStyle: NSDateFormatterStyle.NoStyle, timeStyle: NSDateFormatterStyle.NoStyle)

我希望将其更改为：

如果日期是今天，日期=“HH：MM”
如果日期是昨天，则日期=“昨天”
如果日期是前天等，则日期=“星期一，星期二，星期三......”
如果日期超过1周，则日期= MM / DD / YY

Answer 1

或试试这个。请注意，我们必须使用components:fromDate:，然后使用components:fromDateComponents:toDateComponents:options:，因为如果我们不在晚上23:59返回23:59而不是昨天。

extension NSDateFormatter {
    static func friendlyStringForDate(date:NSDate) -> String {
        // Fetch the default calendar
        let calendar = NSCalendar.currentCalendar()

        // Compute components from target date
        let from = calendar.components([.Day, .Month, .Year], fromDate: date)

        // Compute components from current date
        let to = calendar.components([.Day, .Month, .Year], fromDate: NSDate())

        // Compute days difference between the two
        let delta = calendar.components(.Day, fromDateComponents: from, toDateComponents: to, options: [])

        switch delta.day {
        case 0:
            let formatter = NSDateFormatter()
            formatter.timeZone = NSTimeZone.defaultTimeZone()
            formatter.dateFormat = "HH:mm"
            return formatter.stringFromDate(date)

        case 1:
            return "Yesterday"

        case 2..<7:
            let formatter = NSDateFormatter()
            formatter.timeStyle = .NoStyle
            formatter.dateFormat = "EEEE"
            return formatter.stringFromDate(date)

        default:
            let formatter = NSDateFormatter()
            formatter.timeStyle = .NoStyle
             formatter.dateFormat = "MM/dd/YY"
            return formatter.stringFromDate(date)
        }
    }
}

现在，只使用它：

timeLabel.text = NSDateFormatter.friendlyStringForDate(date!)

Answer 2

SWIFT 3：

extension DateFormatter {

    static func friendlyStringForDate(date: Date) -> String {
        // Fetch the default calendar
        let calendar = Calendar.current
        let unitFlags: NSCalendar.Unit = [.day]

        // Compute days difference between the two
        let delta = (calendar as NSCalendar).components(unitFlags, from: date, to: Date(), options: [])

        if let day = delta.day {

            switch day {
            case 0:
                let formatter = DateFormatter()
                formatter.timeZone = NSTimeZone.default
                formatter.dateFormat = "hh:mm a"
                return formatter.string(from: date)

            case 1:
                return "Yesterday"

            case 2..<7:
                let formatter = DateFormatter()
                formatter.timeStyle = .none
                formatter.dateFormat = "EEEE"
                return formatter.string(from: date)

            default:
                let formatter = DateFormatter()
                formatter.timeStyle = .none
                formatter.dateFormat = "MM/dd/YY"
                return formatter.string(from: date)
            }
        }
        return ""
    }
}

NSDateFormatter。在swift

2 个答案: