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
Swift 3更新:
let date = Date()
let calendar = Calendar.current
let hour = calendar.component(.hour, from: date)
let minutes = calendar.component(.minute, from: date)
我是这样做的:
let date = NSDate()
let calendar = NSCalendar.currentCalendar()
let components = calendar.components(.CalendarUnitHour | .CalendarUnitMinute, fromDate: date)
let hour = components.hour
let minutes = components.minute
在objective-c中看到同样的问题，我如何从NSDate中获得小时和分钟?
和Nate的答案相比，你得到的是数字，而不是字符串……
其他回答
迅速回答:
let date = NSDate()
let calendar = NSCalendar.currentCalendar()
let components = calendar.components([.Hour, .Minute], fromDate: date)
let hour = components.hour
let minutes = components.minute
斯威夫特3:
static func currentTime() -> String {
let date = Date()
let calendar = Calendar.current
let hour = calendar.component(.hour, from: date)
let minutes = calendar.component(.minute, from: date)
return "\(hour):\(minutes)"
}
PS -不确定将当前时间(和小时)作为日期时间是什么意思，但希望上面的解释足以回答这个问题。
使用Date Formatter -Swift 3.0
//Date
let dateFormatter = DateFormatter()
dateFormatter.dateStyle = .medium
let dateString = "Current date is: \(dateFormatter.string(from: Date() as Date))"
labelfordate.text = String(dateString)
//Time
let timeFormatter = DateFormatter()
timeFormatter.timeStyle = .medium
let timeString = "Current time is: \(timeFormatter.string(from: Date() as Date))"
labelfortime.text = String(timeString)
每秒钟更新一次日期和时间
override func viewDidLoad() {
super.viewDidLoad()
timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(DateAndTime.action), userInfo: nil, repeats: true)
}
func action()
{
//Date
let dateFormatter = DateFormatter()
dateFormatter.dateStyle = .medium
let dateString = "Current date is: \(dateFormatter.string(from: Date() as Date))"
labelfordate.text = String(dateString)
//Time
let timeFormatter = DateFormatter()
timeFormatter.timeStyle = .medium
let timeString = "Current time is: \(timeFormatter.string(from: Date() as Date))"
labelfortime.text = String(timeString)
}
注意:定时器代码中的DateAndTime是类名。
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
}
}
使用Swift 5 (Xcode 10 & Xcode 11)(来自法国UTC)
func getCurrentDateTime() {
let now = Date()
let formatter = DateFormatter()
formatter.locale = Locale(identifier: "fr_FR")
formatter.dateFormat = "EEEE dd MMMM YYYY HH:mm"
myLabel.text = formatter.string(from: now)
myLabel.font = UIFont(name: "HelveticaNeue-Light", size: 12)
myLabel.textColor = UIColor.black
}
如果您只想显示日期，请设置formatter.dateFormat
formatter.dateFormat = "EEEE dd MMMM YYYY"
若要只显示小时，请更改格式化程序。dateFormat来
formatter.dateFormat = "HH:mm"
不要忘记在viewDidLoad上添加getCurrentDateTime()。
