获取时间间隔

获取当前时间：

-(NSString *)getCurrentTime
{
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
NSString *dateTime = [formatter stringFromDate:[NSDate date]];
return dateTime;
}
date1代表开始时间，data2是结束时间

NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
NSDate *date1 = [formatter dateFromString:startTime];
NSDate *date2 = [NSDate date];
NSTimeInterval aTimer = [date2 timeIntervalSinceDate:date1];

int hour = (int)(aTimer/3600);
int minute = (int)(aTimer -hour*3600)/60;
int second =aTimer - hour*3600 -minute*60;
NSString *dural = [NSString stringWithFormat:@"%d时%d分%d秒",hour, minute,second];