使用 swift 3 和 xcode 8 的 2 个日期（以周和天为单位）之间的差异

Question

我正在尝试在几周和几天内计算 2 个日期（一个是当前日期，另一个来自日期选择器）之间的差异，然后在标签上显示结果，这就是我到目前为止所做的，我很感激在这里获得更有经验的开发人员的帮助！

let EDD = datePicker.date
let now = NSDate()

let formatter = DateComponentsFormatter()
formatter.unitsStyle = .short
formatter.allowedUnits = [.day]
formatter.maximumUnitCount = 2   

let string = formatter.string (from: now as Date, to: EDD)

label.text = string

Answer 1

您可以使用 Calendar 的 dateComponents(_:from:to:) 来计算 2 个日期与所需单位之间的差异。

示例：

let dateRangeStart = Date()
let dateRangeEnd = Date().addingTimeInterval(12345678)
let components = Calendar.current.dateComponents([.weekOfYear, .month], from: dateRangeStart, to: dateRangeEnd)

print(dateRangeStart)
print(dateRangeEnd)
print("difference is \(components.month ?? 0) months and \(components.weekOfYear ?? 0) weeks")


> 2017-02-17 10:05:19 +0000
> 2017-07-10 07:26:37 +0000
> difference is 4 months and 3 weeks

let months = components.month ?? 0
let weeks = components.weekOfYear ?? 0

Answer 2

你很接近。只需添加 .weekOfMonth（意思是 "quantity of weeks" 根据 API 文档）到允许的单位。示例：

let now = Date()
let endDate = now.addingTimeInterval(24 * 3600 * 17)

let formatter = DateComponentsFormatter()
formatter.allowedUnits = [.day, .weekOfMonth]
formatter.unitsStyle = .full
let string = formatter.string(from: now, to: endDate)!

print(string) // 2 weeks, 3 days

不需要设置maximumUnitCount = 2因为有只有两个允许的单位。

Answer 3

Swift 4

使用 Xcode 版本 9.2

进行测试

combining the above two answers that helps me

使用以下方法通过两个日期之间的差异获取字符串，其想法是通过格式本地化单词周/天/分钟。

func getTimeComponentString(olderDate older: Date,newerDate newer: Date) -> (String?)  {
    let formatter = DateComponentsFormatter()
    formatter.unitsStyle = .full

    let componentsLeftTime = Calendar.current.dateComponents([.minute , .hour , .day,.month, .weekOfMonth,.year], from: older, to: newer)

    let year = componentsLeftTime.year ?? 0
    if  year > 0 {
        formatter.allowedUnits = [.year]
        return formatter.string(from: older, to: newer)
    }


    let month = componentsLeftTime.month ?? 0
    if  month > 0 {
        formatter.allowedUnits = [.month]
        return formatter.string(from: older, to: newer)
    }

    let weekOfMonth = componentsLeftTime.weekOfMonth ?? 0
    if  weekOfMonth > 0 {
        formatter.allowedUnits = [.weekOfMonth]
        return formatter.string(from: older, to: newer)
    }

    let day = componentsLeftTime.day ?? 0
    if  day > 0 {
        formatter.allowedUnits = [.day]
        return formatter.string(from: older, to: newer)
    }

    let hour = componentsLeftTime.hour ?? 0
    if  hour > 0 {
        formatter.allowedUnits = [.hour]
        return formatter.string(from: older, to: newer)
    }

    let minute = componentsLeftTime.minute ?? 0
    if  minute > 0 {
        formatter.allowedUnits = [.minute]
        return formatter.string(from: older, to: newer) ?? ""
    }

    return nil
}

这是您可以使用的方法

    let nowDate = Date()
    let endDate = Date().addingTimeInterval(12345678)

    let string =  String.getTimeComponentString(olderDate: nowDate, newerDate: endDate)!
    print(nowDate)
    print(endDate)
    print(string)

Output
2018-03-0808:11:22+0000
2018-07-29 05:32:41 +0000
4个月

Answer 4

Swift 4,5

你可以用这一行代码找到以周为单位的不同日期。

let totalWeeks = Calendar.current.dateComponents([.weekOfMonth], from: Date(), to: endDate).weekOfMonth!

//for totalDays
let totalDays = Calendar.current.dateComponents([.day], from: Date(), to: endDate).day!

使用 swift 3 和 xcode 8 的 2 个日期（以周和天为单位）之间的差异

Difference between 2 dates in weeks and days using swift 3 and xcode 8

date-comparison

swift

Swift 4

使用 Xcode 版本 9.2

这是您可以使用的方法