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
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
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)
您可以在Date上创建一个扩展，这样您就可以轻松地在其他文件中调用它。下面是一个使用计算属性的日期扩展示例。
它会打印出来:“今天，下午4:55”
extension Date {
var formatter: DateFormatter? {
let formatter = DateFormatter()
formatter.dateStyle = .short
formatter.timeStyle = .short
formatter.doesRelativeDateFormatting = true
return formatter
}
}
扩展noiiv的史诗般的简洁解决方案，这里是更简洁的Swift 3/4实现:
斯威夫特3/4
let components = Calendar.current.dateComponents([.hour, .minute], from: Date())
let (hour, minute) = (components.hour, components.minute)
同时，扩展Leo Dabus的扩展，我们可以有:
extension Date {
func components(_ components: Set<Calendar.Component>) -> DateComponents {
return Calendar.current.dateComponents(components, from: self)
}
func component(_ component: Calendar.Component) -> Int {
return Calendar.current.component(component, from: self)
}
var era: Int { return component(.era) }
var year: Int { return component(.year) }
var month: Int { return component(.month) }
var day: Int { return component(.day) }
var hour: Int { return component(.hour) }
var minute: Int { return component(.minute) }
var second: Int { return component(.second) }
var weekday: Int { return component(.weekday) }
var weekdayOrdinal: Int { return component(.weekdayOrdinal) }
var quarter: Int { return component(.quarter) }
var weekOfMonth: Int { return component(.weekOfMonth) }
var weekOfYear: Int { return component(.weekOfYear) }
var yearForWeekOfYear: Int { return component(.yearForWeekOfYear) }
var nanosecond: Int { return component(.nanosecond) }
var calendar: Calendar? { return components([.calendar]).calendar }
var timeZone: TimeZone? { return components([.timeZone]).timeZone }
}
像这样使用它:
let date = Date()
let (hour, minute) = (date.hour, date.minute)
func getCurrentDate() -> Date {
let date = Date()
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd"
let dateInString = dateFormatter.string(from: date)
let dateinDate = dateFormatter.date(from: dateInString)
return dateinDate!
}
一行Swift 5.2
let date = String(DateFormatter.localizedString(from: Date(), dateStyle: .medium, timeStyle: .short))
