我怎么能得到一个NSDate对象的年/月/日，没有其他信息?我意识到我可以用类似这样的东西来做这件事:
NSCalendar *cal = [[NSCalendar alloc] init];
NSDateComponents *components = [cal components:0 fromDate:date];
int year = [components year];
int month = [components month];
int day = [components day];
但是对于像获取NSDate的年/月/日这样简单的事情来说，这似乎是一大堆麻烦。还有其他解决办法吗?
当前回答
你可以使用NSDateFormatter获取NSDate的独立组件:
NSDateFormatter *df = [[NSDateFormatter alloc] init];
[df setDateFormat:@"dd"];
myDayString = [df stringFromDate:[NSDate date]];
[df setDateFormat:@"MMM"];
myMonthString = [df stringFromDate:[NSDate date]];
[df setDateFormat:@"yy"];
myYearString = [df stringFromDate:[NSDate date]];
如果你想要得到月份的数字而不是缩写，请使用“MM”。如果你想获取整数，使用[myDayString intValue];
其他回答
下面是Swift的解决方案:
let todayDate = NSDate()
let calendar = NSCalendar(identifier: NSCalendarIdentifierGregorian)!
// Use a mask to extract the required components. Extract only the required components, since it'll be expensive to compute all available values.
let components = calendar.components(.CalendarUnitYear | .CalendarUnitMonth | .CalendarUnitDay, fromDate: todayDate)
var (year, month, date) = (components.year, components.month, components.day)
快2.倍
extension NSDate {
func currentDateInDayMonthYear() -> String {
let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "d LLLL yyyy"
return dateFormatter.stringFromDate(self)
}
}
你可以用它作为
NSDate().currentDateInDayMonthYear()
输出
6 March 2016
我写这个答案是因为这是唯一的方法，不给你可选的NSDateComponent变量和/或强制展开这些变量(也适用于Swift 3)。
斯威夫特3
let date = Date()
let cal = Calendar.current
let year = cal.component(.year, from: date)
let month = cal.component(.month, from: date)
let day = cal.component(.day, from: date)
斯威夫特2
let date = NSDate()
let cal = NSCalendar.currentCalendar()
let year = cal.component(.Year, fromDate: date)
let month = cal.component(.Month, fromDate: date)
let day = cal.component(.Day, fromDate: date)
奖金Swift 3有趣的版本
let date = Date()
let component = { (unit) in return Calendar.current().component(unit, from: date) }
let year = component(.year)
let month = component(.month)
let day = component(.day)
如果你的目标是iOS 8+，你可以使用新的NSCalendar方便方法以更简洁的格式实现这一点。
首先创建一个NSCalendar并使用所需的NSDate。
NSCalendar *calendar = [NSCalendar currentCalendar];
NSDate *date = [NSDate date];
你可以通过component:fromDate单独提取组件:
NSInteger year = [calendar component:NSCalendarUnitYear fromDate:date];
NSInteger month = [calendar component:NSCalendarUnitMonth fromDate:date];
NSInteger day = [calendar component:NSCalendarUnitDay fromDate:date];
或者，更简洁地，通过getEra使用NSInteger指针:year:month:day:fromDate:
NSInteger year, month, day;
[calendar getEra:nil year:&year month:&month day:&day fromDate:date];
要了解更多信息和示例，请查看iOS 8中简化的NSDate操作。免责声明，这是我写的文章。
从iOS 8.0(和OS X 10)开始，你可以使用component方法来简化获取单个日期组件，如下所示:
int year = [[NSCalendar currentCalendar] component:NSCalendarUnitYear fromDate:[NSDate date]];
应该使事情更简单，希望这是有效地实施。
