从Date开始的Swift显示时间(NSDate)

Question

在一个单元格中,我想在Parse服务器中显示NSDate的时间.这是代码,但它不起作用.什么都没有改变,数据没有被解析.

    if let createdat = (object?["createdAt"] as? String){
            let pastDate = Date(timeIntervalSinceNow: TimeInterval(createdat)!)
            cell.TimeAgo.text = pastDate.timeAgoDisplay()
        }


       extension Date {
          func timeAgoDisplay() -> String {
        let secondsAgo = Int(Date().timeIntervalSince(self))

        let minute = 60
        let hour = 60 * minute
        let day = 24 * hour
        let week = 7 * day

        if secondsAgo < minute {
            return "\(secondsAgo) sec ago"
        } else if secondsAgo < hour {
            return "\(secondsAgo / minute) min ago"
        } else if secondsAgo < day {
            return "\(secondsAgo / hour) hrs ago"
        } else if secondsAgo < week {
            return "\(secondsAgo / day) days ago"
        }

        return "\(secondsAgo / week) weeks ago"
    }
}

Answer 1

如果您只想要Date的Time Ago扩展,请转到答案的底部

我会告诉你一个例子,只是为了几秒钟之前,我会更新你的扩展程序.

注意:如果需要,您可以直接使用Pase中的日期:

if let pastDate = (object?["createdAt"] as? Date){
        cell.TimeAgo.text = pastDate.timeAgoDisplay()
    }

示例如何使用Swift 3或Swift 4获取秒数:

第一:要获得秒数,我们需要检查是否有一分钟或更短时间,要获得当前日期减去一分钟,您可以写下:

let minuteAgo = calendar.date(byAdding: .minute, value: -1, to: Date())!

第二:现在比较两个日期!(如果你的扩展我们自己替换你的日期)并获得这2个日期之间的差异.

if (minuteAgo < yourDate) {
    let diff = Calendar.current.dateComponents([.second], from: yourDate, to: Date()).second ?? 0
    print("\(diff) sec ago")
}

这就是全部,现在你可以打印时间了!

所以你的扩展是这样的:(这是一个简单的扩展来获取时间)

extension Date {
    func timeAgoDisplay() -> String {

        let calendar = Calendar.current
        let minuteAgo = calendar.date(byAdding: .minute, value: -1, to: Date())!
        let hourAgo = calendar.date(byAdding: .hour, value: -1, to: Date())!
        let dayAgo = calendar.date(byAdding: .day, value: -1, to: Date())!
        let weekAgo = calendar.date(byAdding: .day, value: -7, to: Date())!

        if minuteAgo < self {
            let diff = Calendar.current.dateComponents([.second], from: self, to: Date()).second ?? 0
            return "\(diff) sec ago"
        } else if hourAgo < self {
            let diff = Calendar.current.dateComponents([.minute], from: self, to: Date()).minute ?? 0
            return "\(diff) min ago"
        } else if dayAgo < self {
            let diff = Calendar.current.dateComponents([.hour], from: self, to: Date()).hour ?? 0
            return "\(diff) hrs ago"
        } else if weekAgo < self {
            let diff = Calendar.current.dateComponents([.day], from: self, to: Date()).day ?? 0
            return "\(diff) days ago"
        }
        let diff = Calendar.current.dateComponents([.weekOfYear], from: self, to: Date()).weekOfYear ?? 0
        return "\(diff) weeks ago"
    }
}

要使用它,这非常简单:

var now = Date()
now.timeAgoDisplay()

Answer 2

斯威夫特 5.1 (iOS 13)

从 iOS 13 开始，您可以使用 Apple 的RelativeDateFormatter。优点是生成的字符串是本地化的。

let date = Date().addingTimeInterval(-15000)

let formatter = RelativeDateTimeFormatter()
formatter.unitsStyle = .full
let string = formatter.localizedString(for: date, relativeTo: Date())

print(string) // 4 hours ago

例如，请参阅此博客文章。

Answer 3

这是 Swift 5 中的解决方案：

extension Date {

func timeAgo() -> String {

    let secondsAgo = Int(Date().timeIntervalSince(self))

    let minute = 60
    let hour = 60 * minute
    let day = 24 * hour
    let week = 7 * day
    let month = 4 * week

    let quotient: Int
    let unit: String
    if secondsAgo < minute {
        quotient = secondsAgo
        unit = "second"
    } else if secondsAgo < hour {
        quotient = secondsAgo / minute
        unit = "min"
    } else if secondsAgo < day {
        quotient = secondsAgo / hour
        unit = "hour"
    } else if secondsAgo < week {
        quotient = secondsAgo / day
        unit = "day"
    } else if secondsAgo < month {
        quotient = secondsAgo / week
        unit = "week"
    } else {
        quotient = secondsAgo / month
        unit = "month"
    }
    return "\(quotient) \(unit)\(quotient == 1 ? "" : "s") ago"
}
}

Answer 4

有点棘手）

基本上你需要

• 检查间隔
• 选择感兴趣的组件
• 检查是否需要商以及它是否适用于当前语言

iOS 提供了几种方法来做到这一点

1. DateComponentsFormatter

   +：无法处理本地化和其他与字符串相关的内容

   -：不太灵活

   let formatter = DateComponentsFormatter()
   formatter.allowedUnits = [.hour, .minute, .second]
   formatter.unitsStyle = .brief
   formatter.zeroFormattingBehavior = .dropAll
   
   let result = formatter.string(from: Date().advanced(by: -300), to: Date())
   result
   

结果：

“5分钟”

2. RelativeDateTimeFormatter

   +：无法处理本地化和其他与字符串相关的内容

   -：iOS13+

   let formatter = RelativeDateTimeFormatter()
   formatter.unitsStyle = .full
   return formatter.localizedString(for: self, relativeTo: Date())
   

3. 定制方式

   +：灵活

   -：编码一切

样本：

import Foundation

public extension Date {

  struct DetailedDateSuffix {

    let year: String
    let month: String
    let week: String
    let day: String
    let hour: String
    let min: String
    let second: String

    let quotient: String
    let suffix: String

    public init(year: String,
                week: String,
                month: String,
                day: String,
                hour: String,
                min: String,
                second: String,
                quotient: String,
                suffix: String = String.empty) {
      self.year = year
      self.month = month
      self.week = week
      self.day = day
      self.hour = hour
      self.min = min
      self.second = second
      self.quotient = quotient
      self.suffix = suffix
    }
  }

  func toDetailedReadableFormat(_ suffix: DetailedDateSuffix) -> String {

    if #available(iOS 13.0, *) {
      let formatter = RelativeDateTimeFormatter()
      formatter.unitsStyle = .full
      return formatter.localizedString(for: self, relativeTo: Date())
    } else {
      let calendar = Calendar.current
      let ageComponents = calendar.dateComponents(
        [
          .year,
          .month,
          .weekOfYear,
          .day,
          .hour,
          .minute,
          .second
        ],
        from: self,
        to: Date())

      var description: String = String.empty

      if let years = ageComponents.year,
        let months = ageComponents.month,
        let weeks = ageComponents.weekOfYear,
        let days = ageComponents.day,
        let hours = ageComponents.hour,
        let min = ageComponents.minute,
        let sec = ageComponents.second {

        var requireQuotient = false

        if years > 0 {
          description = "\(years)" + suffix.year
          requireQuotient = years == 1
        } else if months > 0 {
          description = "\(months)" + suffix.month
          requireQuotient = months == 1
        } else if weeks > 0 {
          description = "\(weeks)" + suffix.week
          requireQuotient = weeks == 1
        } else if days > 0 {
          description = "\(days)" + suffix.day
          requireQuotient = days == 1
        } else if hours > 0 {
          description = "\(hours)" + suffix.hour
          requireQuotient = hours == 1
        } else if min > 0 {
          description = "\(min)" + suffix.min
          requireQuotient = min == 1
        } else if sec > 0 {
          description = "\(sec)" + suffix.second
          requireQuotient = sec == 1
        }

        description = requireQuotient ? "\(description)\(suffix.quotient)" : description
        description = "\(description)\(suffix.suffix)"
      }

      return description
    }
  }
}