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
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
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。
我这样做....
NSDate * mydate = [NSDate date];
NSCalendar * mycalendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSCalendarUnit units = NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay;
NSDateComponents * myComponents = [mycalendar components:units fromDate:mydate];
NSLog(@"%d-%d-%d",myComponents.day,myComponents.month,myComponents.year);
NSDate *currDate = [NSDate date];
NSCalendar* calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents* components = [calendar components:NSDayCalendarUnit|NSMonthCalendarUnit|NSYearCalendarUnit fromDate:currDate];
NSInteger day = [components day];
NSInteger month = [components month];
NSInteger year = [components year];
NSLog(@"%d/%d/%d", day, month, year);
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)
斯威夫特
更简单的方法获得date的任何元素作为可选String。
extension Date {
// Year
var currentYear: String? {
return getDateComponent(dateFormat: "yy")
//return getDateComponent(dateFormat: "yyyy")
}
// Month
var currentMonth: String? {
return getDateComponent(dateFormat: "M")
//return getDateComponent(dateFormat: "MM")
//return getDateComponent(dateFormat: "MMM")
//return getDateComponent(dateFormat: "MMMM")
}
// Day
var currentDay: String? {
return getDateComponent(dateFormat: "dd")
//return getDateComponent(dateFormat: "d")
}
func getDateComponent(dateFormat: String) -> String? {
let format = DateFormatter()
format.dateFormat = dateFormat
return format.string(from: self)
}
}
let today = Date()
print("Current Year - \(today.currentYear)") // result Current Year - Optional("2017")
print("Current Month - \(today.currentMonth)") // result Current Month - Optional("7")
print("Current Day - \(today.currentDay)") // result Current Day - Optional("10")
