Question

这是我用于在navigationBar中增加一天的方法，并将当天的名称设置为标题。我知道这是错的，因为我每次调用时都设置“今天”变量。但是每次调用这种方法时我都无法弄清楚如何增加+1天。

-(void)stepToNextDay:(id)sender
{
    today = [NSDate date];
    NSDate *datePlusOneDay = [today dateByAddibgTimeInterval:(60 * 60 * 24)];
    NSDateFormatter *dateformatterBehaviour = [[[NSDateFormatter alloc]init]autorelease];
    [dateFormatter setDateFormat:@"EEEE"];
    NSString *dateString = [dateFormatter stringFromDate:datePlusOneDay];
    self.navigationItem.title = datestring;
}

Answer 1

将您所显示的日期存储在视图控制器的属性（ivar，...）中。这样，当你去第二天时，你可以检索当前的设置。

如果要可靠地添加日期，请使用NSCalendar和NSDateComponents获取“1天”单位，并将其添加到当前日期。

NSCalendar*       calendar = [[[NSCalendar alloc] initWithCalendarIdentifier: NSGregorianCalendar] autorelease];
NSDateComponents* components = [[[NSDateComponents alloc] init] autorelease];
components.day = 1;
NSDate* newDate = [calendar dateByAddingComponents: components toDate: self.date options: 0];

Answer 2

从iOS 8 NSGregorianCalendar不推荐使用，更新后的答案为

NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];
NSDateComponents *components = [[NSDateComponents alloc] init];
components.day = 1;
NSDate *newDate = [calendar dateByAddingComponents:components toDate:today options:0];

Swift代码：

var today:NSDate = NSDate()
let calender:NSCalendar! = NSCalendar(calendarIdentifier: NSCalendarIdentifierGregorian)
var components:NSDateComponents = NSDateComponents()
components.setValue(1, forComponent: NSCalendarUnit.CalendarUnitDay)
var newDate:NSDate! = calender.dateByAddingComponents(components, toDate:today, options: NSCalendarOptions(0))

增加NSDate +1天方法Objective-C？

2 个答案: