iOS开发:用NSTimer实现倒计时
首先定义NSTimer
NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(timerFireMethod:) userInfo:nil repeats:YES];
倒计时在timer的触发方法里完成
- (void)timerFireMethod:(NSTimer *)timer
{
NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *components = [[NSDateComponents alloc] init];
[components setYear:2012];
[components setMonth:8];
[components setDay:13];
[components setHour:12];
[components setMinute:0];
[components setSecond:0];
NSDate *fireDate = [calendar dateFromComponents:components];//目标时间
NSDate *today = [NSDate date];//当前时间
unsigned int unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit;
NSDateComponents *d = [calendar components:unitFlags fromDate:today toDate:fireDate options:0];//计算时间差
auctionTime.text = [NSString stringWithFormat:@"%d天%d小时%d%分%d秒", [d day], [d hour], [d minute], [d second]];//倒计时显示
}
这样就完成了倒计时。
不过如果有专门的服务器时,要把服务器和自己本机的时间差考虑进去