ios - 你如何在 objective-c 中生成一个随机日期？

Question

我想在两个日期之间生成一个随机日期 - 例如，今天和从现在起 60 天之间的随机日期。我该怎么做？

更新

根据答案中的信息，我想到了这个我经常使用的方法:

// Generate a random date sometime between now and n days before day.
// Also, generate a random time to go with the day while we are at it.
- (NSDate *) generateRandomDateWithinDaysBeforeToday:(NSInteger)days
{
    int r1 = arc4random_uniform(days);
    int r2 = arc4random_uniform(23);
    int r3 = arc4random_uniform(59);

    NSDate *today = [NSDate new];
    NSCalendar *gregorian = 
             [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];

    NSDateComponents *offsetComponents = [NSDateComponents new];
    [offsetComponents setDay:(r1*-1)];
    [offsetComponents setHour:r2];
    [offsetComponents setMinute:r3];

    NSDate *rndDate1 = [gregorian dateByAddingComponents:offsetComponents 
                                                  toDate:today options:0];

    return rndDate1;
}

Answer 1

获取一个随机数并将其用作时间间隔，然后将其添加到开始日期。例如

NSTimeInterval timeBetweenDates = [endDate timeIntervalSinceDate:startDate];
NSTimeInterval randomInterval = ((NSTimeInterval)arc4random() / ARC4RANDOM_MAX) * timeBetweenDates;

NSDate *randomDate = [startDate dateByAddingTimeInterval:randomInterval];