Question

我有这个内部日期扩展似乎不再适用于Swift 3：

internal extension DateComponents {
    func to12pm() {
        self.hour = 12
        self.minute = 0
        self.second = 0
    }
}

错误消息是：

无法分配属性：'self'是不可变的

如何在Swift 3中实现这一目标？

其他信息（如果需要）：此日期扩展程序调用了它：

func endOfWeek(_ weekday: Int) -> Date? {
    guard
        let cal = Calendar.current,
        var comp: DateComponents = (cal as Calendar).components([.weekOfYear], from: self)
        else {
            return nil
    }
    comp.weekOfYear = 1
    comp.day -= 1
    comp.to12pm()
    return (cal as NSCalendar).date(byAdding: comp, to: self.startOfWeek(weekday)!, options: [])!
}

现在在Swift 3中看起来像这样：

func endOfWeek(_ weekday: Int) -> Date? {
    let cal = Calendar.current
    var comp = cal.dateComponents([.weekOfYear], from: self)
    comp.weekOfYear = 1
    comp.day? -= 1
    //This does not have the "comp.to12pm()" that the Swift 2 version did
    return cal.date(byAdding: comp, to: self.startOfWeek(weekday)!)!
}

Answer 1

DateComponents现在是一个结构，它解释了这个错误的原因：

无法分配属性：＆＃39; self＆＃39;是不可改变的

您需要从self创建一个新的var，更改它并按如下方式返回：

-app
    -templates
         -admin
              change_list.html

Swift 3：设置时间的内部扩展

1 个答案: