ios - 如何找到生日中的剩余天数

Question

我想使用以下代码从生日数组中恢复天数

for(int i =0;i<_convertedBdates.count;i++){

    NSDateFormatter *tempFormatter = [[NSDateFormatter alloc]init];
    [tempFormatter setDateFormat:@"dd/MM/YYYY"];
    NSDate *firstdate = [tempFormatter dateFromString:[_convertedBdates objectAtIndex:i]];


    NSString *curYear = [tempFormatter stringFromDate:[NSDate date]];
    NSDate *secondDate = [tempFormatter dateFromString:curYear];
    NSTimeInterval lastDiff = [firstdate timeIntervalSinceNow];
    NSTimeInterval todaysDiff = [secondDate timeIntervalSinceNow];
    NSTimeInterval dateDiff = lastDiff  - todaysDiff;
    int day = dateDiff/(3600*24);

    NSLog(@" _newlymadeArray %@",[_convertedBdates objectAtIndex:i]);

    NSLog(@" days %d",day);
    [_daysremaining addObject:[NSString stringWithFormat:@"%d",day] ];
    }
    NSLog(@" days %@",_daysremaining);

我做错了什么为什么我没有得到正确的日子

Answer 1

for(int i =0;i<_convertedBdates.count;i++){
    NSDateFormatter *tempFormatter = [[NSDateFormatter alloc]init];
    [tempFormatter setDateFormat:@"dd/MM/YYYY"];
    NSDate *firstdate = [tempFormatter dateFromString:[_convertedBdates objectAtIndex:i]];

    NSString *curYear = [tempFormatter stringFromDate:[NSDate date]];
    NSDate *secondDate = [tempFormatter dateFromString:curYear];
    NSTimeInterval lastDiff = [firstdate timeIntervalSinceNow];
    NSTimeInterval todaysDiff = [secondDate timeIntervalSinceNow];
    NSTimeInterval dateDiff = lastDiff  - todaysDiff;
    int day = dateDiff/(3600*24);
    day = day -1;
    NSLog(@" _newlymadeArray %@",[_convertedBdates objectAtIndex:i]);

    NSLog(@" days %d",day);
    [_daysremaining addObject:[NSString stringWithFormat:@"%d",day] ];
}
NSLog(@" days %@",_daysremaining);

Answer 2

试试这样它会帮助你，

NSString *start = @"03/12/2013";
NSString *end = @"09/12/2013";

NSDateFormatter *f = [[NSDateFormatter alloc] init];
[f setDateFormat:@"dd/mm/yyyy"];
NSDate *startDate = [f dateFromString:start];
NSDate *endDate = [f dateFromString:end];

NSCalendar *gregorianCalendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *components = [gregorianCalendar components:NSDayCalendarUnit
                                                    fromDate:startDate
                                                      toDate:endDate
                                                     options:0];
NSLog(@"%d",[components day]);

Answer 3

保持代码简单：

您可以使用一种方法并在计算块中调用它：

- (NSInteger)daysBetweenDate:(NSDate*)fromDateTime andDate:(NSDate*)toDateTime{
    NSDate *fromDate;
    NSDate *toDate;

    NSCalendar *calendar=[NSCalendar currentCalendar];

    [calendar rangeOfUnit:NSDayCalendarUnit startDate:&fromDate interval:NULL forDate:fromDateTime];
    [calendar rangeOfUnit:NSDayCalendarUnit startDate:&toDate interval:NULL forDate:toDateTime];

    NSDateComponents *difference = [calendar components:NSDayCalendarUnit
        fromDate:fromDate toDate:toDate options:0];

    return [difference day];
}