倒计时 - iPhone倒计时器

Question

我正在尝试制作一个计数器，显示我们离开前往欧洲的天数。截至今天，只有大约70天，所以我不认为需要担心天文数字之类的问题，但我真的感到困惑 - 我附上了一些朋友给我的代码，但它们也无法正常工作。相信我，当我说我已经尽我所能时，请不要咬我的头，我在这些论坛上看到过这样的事情，是的，我确实广泛地查看了苹果文档，但我不确定从哪里开始 - 我尝试了NSTimer、NSDate及其所有子类和方法，但没有什么是立即显而易见的。

就我认为我应该做什么而言，我认为我需要为今天/现在/当前日期分配一个整数值，这将使用[NSDate date]动态更改，然后对于我们离开的日期也是如此。倒计时只是在再次调用该方法时更新（如果需要，我可以使用NSTimer进行此操作），在倒计时上显示的值是这两个值之间的差异。

我并不特别希望有一种闪烁的东西，每秒更新一次，直到我们离开 - 我个人认为那很俗气，但如果有人知道怎么做，我会感激未来的参考。

我还进行了广泛的谷歌搜索，但可能只是使用了错误的搜索词，但我也找不到任何东西。

非常感谢您的帮助。

谢谢。

Michaeljvdw

- (void)countDownMethod {
NSDateComponents *comps = [[NSDateComponents alloc] init];
[comps setDay:startDay];
[comps setMonth:startMonth];
[comps setYear:startYear];
[comps setHour:startHour];

NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDate *date = [gregorian dateFromComponents:comps];
NSLog(@"%@",date);
[gregorian release];
[comps release];
NSTimeInterval diff = [date timeIntervalSinceNow];

int diffInt = diff;

NSString *days = [NSString stringWithFormat:@"%d",diffInt/86400];
day0.text = @"0";   
day1.text = @"0";
day2.text = @"0";
NSLog(@"Days Length: %d",days.length);

if(days.length >= 1){
    day2.text = [days substringFromIndex:days.length - 1];

    if(days.length >= 2){
        day1.text = [days substringWithRange:NSMakeRange(days.length - 2, 1)];

        if(days.length >= 3){
            day0.text = [days substringWithRange:NSMakeRange(days.length - 3, 1)];
        }
    }
}

NSString *hours = [NSString stringWithFormat:@"%d",(diffInt%86400)/3600];
hour0.text = @"0";
hour1.text = @"0";
NSLog(@"Hours Length: %d",hours.length);

if(hours.length >= 1){
    hour1.text = [hours substringFromIndex:hours.length - 1];

    if(hours.length >= 2){
        hour0.text = [hours substringWithRange:NSMakeRange(hours.length - 2, 1)];
    }
}
NSString *minutes = [NSString stringWithFormat:@"%d",((diffInt%86400)%3600)/60];
minute0.text = @"0";
minute1.text = @"0";
NSLog(@"Minutes Length: %d",minutes.length);

if(minutes.length >= 1){
    minute1.text = [minutes substringFromIndex:minutes.length - 1];

    if(minutes.length >= 2){
        minute0.text = [minutes substringWithRange:NSMakeRange(minutes.length - 2, 1)];
    }
}

}

- Michaeljvdw

Answer 1

如果您知道两个日期之间的秒数（NSTimeInterval），那么您可以按照以下方式将其轻松转换为格式为天：小时：分钟：秒的字符串。

- (NSString*)secsToDaysHoursMinutesSecondsString:(NSTimeInterval)theSeconds {
div_t r1 = div(theSeconds, 60*60*24);
NSInteger theDays = r1.quot;
NSInteger secsLeftFromDays = r1.rem;

div_t r2 = div(secsLeftFromDays, 60*60);
NSInteger theHours = r2.quot;
NSInteger secsLeftFromHours = r2.rem;

div_t r3 = div(secsLeftFromHours, 60);
NSInteger theMins = r3.quot;
NSInteger theSecs = r3.rem;

NSString* days;
if (theDays < 10) { // make it 2 digits
    days = [NSString stringWithFormat:@"0%i", theDays];
} else {
    days = [NSString stringWithFormat:@"%i", theDays];
}

NSString* hours;
if (theHours < 10) { // make it 2 digits
    hours = [NSString stringWithFormat:@"0%i", theHours];
} else {
    hours = [NSString stringWithFormat:@"%i", theHours];
}

NSString* mins;
if (theMins < 10) { // make it 2 digits
    mins = [NSString stringWithFormat:@"0%i", theMins];
} else {
    mins = [NSString stringWithFormat:@"%i", theMins];
}

NSString* secs;
if (theSecs < 10) { // make it 2 digits
    secs = [NSString stringWithFormat:@"0%i", theSecs];
} else {
    secs = [NSString stringWithFormat:@"%i", theSecs];
}

return [NSString stringWithFormat:@"%@:%@:%@:%@", days, hours, mins,secs];
}

- regulus6633

Answer 2

    //Another simple way  to get the numbers of days difference to a future day from today.

NSTimeInterval todaysDiff = [todayDate timeIntervalSinceNow];
NSTimeInterval futureDiff = [futureDate timeIntervalSinceNow];
NSTimeInterval dateDiff = futureDiff - todaysDiff;

div_t r1 = div(dateDiff, 60*60*24);
NSInteger theDays = r1.quot;

label.text = [NSString stringWithFormat:@"%i", theDays];

- Devaski