ios - NSDateComponents 的 NSLog 分秒 - 如何显示前导零？

Question

我真的需要帮助。编码结果为2:0:0，格式设置为hh:mm:ss。我希望结果为 2:00:00(当分秒小于 10 时，在分秒前添加 0)。

NSDateFormatter *test = [[NSDateFormatter alloc] init];
[test setDateFormat:@"HH:mm:ss"];
NSDate *date1 = [test dateFromString:@"18:00:00"];
NSDate *date2 = [test dateFromString:@"20:00:00"];
NSCalendar* gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
unsigned int uintFlags =  NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit;
NSDateComponents* differenceComponents = [gregorian components:uintFlags fromDate:date1 toDate:date2 options:0];

NSLog(@"%d:%d:%d",[differenceComponents hour],[differenceComponents minute],[differenceComponents second]);

如何做到这一点？

Answer 1

使用 %02ld 说明符记录，例如:

NSLog(@"%ld:%02ld:%02ld",[differenceComponents hour],[differenceComponents minute],[differenceComponents second]);

输出:

2:00:00

另外创建 NSStrings 如下:

NSString *theString = [NSString stringWithFormat:@"%ld:%02ld:%02ld",[differenceComponents hour],[differenceComponents minute],[differenceComponents second]];
NSLog(@"%@",theString);