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
在Swift 2.0中:
let date = NSDate()
let calendar = NSCalendar(identifier: NSCalendarIdentifierGregorian)!
let components = calendar.components([.Month, .Day], fromDate: date)
let (month, day) = (components.month, components.day)
其他回答
如果你想从NSDate中获得单个的NSDateComponents，你肯定需要Itai Ferber建议的解决方案。但如果你想直接从NSDate到NSString，你可以使用NSDateFormatter。
iOS 8新增功能
ObjC
NSDate *date = [NSDate date];
NSInteger era, year, month, day;
[[NSCalendar currentCalendar] getEra:&era year:&year month:&month day:&day fromDate:date];
斯威夫特
let date = NSDate.init()
var era = 0, year = 0, month = 0, day = 0
NSCalendar.currentCalendar().getEra(&era, year:&year, month:&month, day:&day, fromDate: date)
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)
在Swift 2.0中:
let date = NSDate()
let calendar = NSCalendar(identifier: NSCalendarIdentifierGregorian)!
let components = calendar.components([.Month, .Day], fromDate: date)
let (month, day) = (components.month, components.day)
试试这个……
代码片段:
NSDateComponents *components = [[NSCalendar currentCalendar] components:NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear fromDate:[NSDate date]];
int year = [components year];
int month = [components month];
int day = [components day];
它给出了当前的年、月、日
