ios - 如何显示日期为“今天，4 月 14 日”？

Question

我想展示一些日期

Yesterday, 13 April
Today, 14 April
Tomorrow, 15 April
Tuesday, 4 April
Wednesday 5 April

我试过了

        let date = Date(timeIntervalSince1970: value)

        let dayFormatter = DateFormatter()
        dayFormatter.dateStyle = .medium
        dayFormatter.doesRelativeDateFormatting = true

        let dateFormatter = DateFormatter()
        dateFormatter.dateFormat = "d MMMM"
        whenLabel.text = dayFormatter.string(from: date) + ", " + dateFormatter.string(from: date)

如果日期是今天，它可以正常工作，但是对于其他日期，我会收到 “Apr 5, 2017, 5 April”

我该如何解决这个问题？

Answer 1

根据日期是否是今天，您将需要两个完全不同的格式化程序。 doesRelativeDateFormatting 不会帮助您处理复杂的格式。

从检查开始：

if Calendar.current.isDateInToday(date) {
   // use "Today, " + "d MMMM" pattern
} else {
   // use "EEEE" pattern + "d MMMM" pattern
}

Answer 2

只是为了好玩，这是一个利用本地化相对日期格式的解决方案。

它使用Calendar 的扩展名来确定日期是在昨天、今天还是明天：

extension Calendar {
    func isDateInYesterdayTodayTomorrow(_ date: Date) -> Bool
    {
        return self.isDateInYesterday(date) || self.isDateInToday(date) || self.isDateInTomorrow(date)
    }
}

func relativeDateString(for date: Date, locale : Locale = Locale.current) -> String
{
    let dayFormatter = DateFormatter()
    dayFormatter.locale = locale
    if Calendar.current.isDateInYesterdayTodayTomorrow(date) {
        dayFormatter.dateStyle = .medium
        dayFormatter.doesRelativeDateFormatting = true
    } else {
        dayFormatter.dateFormat = "EEEE"
    }
    let relativeWeekday = dayFormatter.string(from: date)

    let dateFormatter = DateFormatter()
    dateFormatter.locale = locale
    dateFormatter.dateFormat = "d MMMM"
    return  relativeWeekday + ", " + dateFormatter.string(from: date)
}

Answer 3

正如 Sulthan 建议的那样，我刚开始了解这种代码，

let mydate = Date()//my actual date need to display
let dateFormatter = DateFormatter()
if Calendar.current.isDateInToday(mydate) {
     dateFormatter.dateFormat = "'Today,' d MMMM"
}
else if Calendar.current.isDateInYesterday(mydate) {
      dateFormatter.dateFormat = "'Yesterday,' d MMMM"
}
else if Calendar.current.isDateInTomorrow(mydate) {
      dateFormatter.dateFormat = "'Tomorrow,' d MMMM"
}
else{
     dateFormatter.dateFormat = "EEEE, d MMMM"
 }

如果我们有更好的方法，请更新我。谢谢