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
如果你只需要一天中的一小时
let calendar = NSCalendar.currentCalendar()
var hour = calendar.component(.Hour,fromDate: NSDate())
其他回答
你可以使用Swift4或swif5如下所示:
let date = Date()
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd"
let current_date = dateFormatter.string(from: date)
print("current_date-->",current_date)
输出:
2020-03-02
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
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
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。
