从操场开始。我正在尝试创建一个简单的应用程序。

我创建了一个date对象,就像这样:

var date = NSDate()

我怎样才能得到当前的时间?在其他语言中,我可以这样做:

var hour = date.hour

但我找不到任何这样的属性/方法。我找到了一个方法,dateWithCalendarFormat。我应该用这个吗?如果是,怎么做?


当前回答

在Swift 3中,

    let date = Date()
    let calendar = Calendar.current()

    let hour = calendar.component(.hour, from: date)

其他回答

你可以从Dateformatter获取

let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "dd/MM/yyyy"
let dateString = dateFormatter.string(from:Date())
print(dateString)

Xcode 8.2.1•Swift 3.0.2

extension Date {
    var hour: Int { return Calendar.autoupdatingCurrent.component(.hour, from: self) }
}

let date = Date()      // "Mar 16, 2017, 3:43 PM"
let hour = date.hour   // 15

Swift让创建和使用扩展变得非常容易。我创建了一个sharedCode.swift文件,并在其中放入枚举、扩展名和其他有趣的东西。我创建了一个NSDate扩展来添加一些典型的功能,这是费力和丑陋的输入一遍又一遍:

extension NSDate
{
    func hour() -> Int
    {
        //Get Hour
        let calendar = NSCalendar.currentCalendar()
        let components = calendar.components(.Hour, fromDate: self)
        let hour = components.hour

        //Return Hour
        return hour
    }


    func minute() -> Int
    {
        //Get Minute
        let calendar = NSCalendar.currentCalendar()
        let components = calendar.components(.Minute, fromDate: self)
        let minute = components.minute

        //Return Minute
        return minute
    }

    func toShortTimeString() -> String
    {
        //Get Short Time String
        let formatter = NSDateFormatter()
        formatter.timeStyle = .ShortStyle
        let timeString = formatter.stringFromDate(self)

        //Return Short Time String
        return timeString
    }
}

使用这个扩展,你现在可以做一些事情,如:

        //Get Current Date
        let currentDate = NSDate()

        //Test Extensions in Log
        NSLog("(Current Hour = \(currentDate.hour())) (Current Minute = \(currentDate.minute())) (Current Short Time String = \(currentDate.toShortTimeString()))")

在上午11:51会写出来:

(当前小时= 11)(当前分钟= 51)(当前短时间字符串= 11:51 AM)

斯威夫特4:

extension Date
{
    func hour() -> Int
    {
    //Get Hour
    let calendar = Calendar.current
    let components = calendar.component(.hour, from: self)
    let hour = components

    //Return Hour
    return hour
    }


    func minute() -> Int
    {
    //Get Minute
    let calendar = Calendar.current
    let components = calendar.component(.minute, from: self)
    let minute = components

    //Return Minute
    return minute
        }
}

如果你需要以一种特定的方式格式化答案,你可以很容易地使用这个方法,default = "dd-MM-yyyy"。

extension Date {

   func today(format : String = "dd-MM-yyyy") -> String{
      let date = Date()
      let formatter = DateFormatter()
      formatter.dateFormat = format
      return formatter.string(from: date)
   }
}

获取今天的日期现在可以使用

Date().today() or Date().today("dd/MM/yyyy")