Question

我在Xcode中使用以下代码：

(void)updateLabel 
{
    NSDate* now = [NSDate date];
    int hour = 23 - [[now dateWithCalendarFormat:nil timeZone:nil] hourOfDay];
    int min = 59 - [[now dateWithCalendarFormat:nil timeZone:nil] minuteOfHour];
    int sec = 59 - [[now dateWithCalendarFormat:nil timeZone:nil] secondOfMinute];
    countdownLabel.text = [NSString stringWithFormat:@"%02d:%02d:%02d", hour, min,sec];
}

我收到以下错误。我该如何解决这个问题？

错误：二进制操作数无效 - （'int'和'id'）

Answer 1

您必须使用这种方式： -

NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *dateComponents = [gregorian components:(NSHourCalendarUnit  | NSMinuteCalendarUnit | NSSecondCalendarUnit) fromDate:[NSDate date]];
NSInteger hour = [dateComponents hour];
NSInteger minute = [dateComponents minute];
NSInteger second = [dateComponents second];
[gregorian release];

希望它可以帮到你

Answer 2

使用这种方式

NSDate* now = [NSDate date];

NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *dateComponents = [gregorian components:(NSHourCalendarUnit  | NSMinuteCalendarUnit | NSSecondCalendarUnit) fromDate:now];
long hour =23-[dateComponents hour];
long min =59-[dateComponents minute];
long sec =59-[dateComponents second];

NSString *str = [NSString stringWithFormat:@"%02ld:%02ld:%02ld", hour, min,sec];
NSLog(@"--> %@",str);

日期计算中的语法错误

2 个答案: