// [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(timerFireMethod:) userInfo:nil repeats:YES];
 
// - (void)timerFireMethod:(NSTimer *)theTimer {
 
 
 
 
BOOL timeStart = YES;
 
 
 
 
NSCalendar *cal = [NSCalendar currentCalendar];
//定义一个NSCalendar对象  
 
 
 
NSDateComponents *endTime = [[NSDateComponents alloc] init];
 
 
 
//初始化目标时间...  
 
 
 
NSDate *today = [NSDate date];
 
 
 
//得到当前时间  
 
 
 
 
 
 
 
 
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
 
 
 
 
[dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
 
 
 
 
NSDate *dateString = [dateFormatter dateFromString:todate];
 
 
 
 
NSString *overdate = [dateFormatter stringFromDate:dateString];
// 
 
 
NSLog(@"overdate=%@",overdate);
 
 
 
 
static int year;
 
 
 
 
static int month;
 
 
 
 
static int day;
 
 
 
 
static int hour;
 
 
 
 
static int minute;
 
 
 
 
static int second;
 
 
 
 
if(timeStart) {
//从NSDate中取出年月日，时分秒，但是只能取一次  
 
 
 
 
 
 
 
year = [[overdate substringWithRange:NSMakeRange(0, 4)] intValue];
 
 
 
 
 
 
 
 
month = [[overdate substringWithRange:NSMakeRange(5, 2)] intValue];
 
 
 
 
 
 
 
 
day = [[overdate substringWithRange:NSMakeRange(8, 2)] intValue];
 
 
 
 
 
 
 
 
hour = [[overdate substringWithRange:NSMakeRange(11, 2)] intValue];
 
 
 
 
 
 
 
 
minute = [[overdate substringWithRange:NSMakeRange(14, 2)] intValue];
 
 
 
 
 
 
 
 
second = [[overdate substringWithRange:NSMakeRange(17, 2)] intValue];
 
 
 
 
 
 
 
 
timeStart= NO;
 
 
 
 
}
 
 
 
 
 
 
 
 
 
[endTime setYear:year];
 
 
 
 
[endTime setMonth:month];
 
 
 
 
[endTime setDay:day];
 
 
 
 
[endTime setHour:hour];
 
 
 
 
[endTime setMinute:minute];
 
 
 
 
[endTime setSecond:second];
 
 
 
 
NSDate *overTime = [cal dateFromComponents:endTime];
//把目标时间装载入date  
 
 
 
//用来得到具体的时差，是为了统一成北京时间  
 
 
 
unsigned int unitFlags = NSYearCalendarUnit| NSMonthCalendarUnit| NSDayCalendarUnit| NSHourCalendarUnit| NSMinuteCalendarUnit| NSSecondCalendarUnit;
 
 
 
 
NSDateComponents *d = [cal components:unitFlags fromDate:today toDate:overTime options:0];
 
 
 
 
NSString *t = [NSString stringWithFormat:@"%d", [d day]];
 
 
 
 
NSString *h = [NSString stringWithFormat:@"%d", [d hour]];
 
 
 
 
NSString *fen = [NSString stringWithFormat:@"%d", [d minute]];
 
 
 
 
if([d minute] < 10) {
 
 
 
 
 
 
 
 
fen = [NSString stringWithFormat:@"0%d",[d minute]];
 
 
 
 
}
 
 
 
 
NSString *miao = [NSString stringWithFormat:@"%d", [d second]];
 
 
 
 
if([d second] < 10) {
 
 
 
 
 
 
 
 
miao = [NSString stringWithFormat:@"0%d",[d second]];
 
 
 
 
}
// 
 
 
NSLog(@"===%@天 %@:%@:%@",t,h,fen,miao);
 
 
 
 
[_longtime setText:[NSString stringWithFormat:@"%@天 %@:%@:%@",t,h,fen,miao]];
 
 
 
 
if([d second] > 0) {
 
 
 
 
 
 
 
 
//计时尚未结束，do_something // 
 
 
 
 
 
 
[_longtime setText:[NSString stringWithFormat:@"%@:%@:%@",d,fen,miao]];
 
 
 
 
}
else if([d second] == 0) {
 
 
 
 
 
 
 
 
//计时结束 do_something  
 
 
 
 
 
 
 
 
 
 
 
 
}
else{
//计时器失效 
 
 
 
 
 
 
 
[theTimer invalidate];
 
 
 
 
}
 
 
 
 
 
}