背景画像を午前6時に1回、午後6時に変更する

Question

午前6時以降に表示する必要がある2枚の画像と、午後6時以降に背景に表示する必要がある夜用画像があります。午前6時〜午後6時と午後6時〜午前6時に自動的に表示を変更してください。

NSDate *_currentDate = [NSDate date]; 
NSDateFormatter *_dateFormatter = [[NSDateFormatter alloc] init]; 
[_dateFormatter setDateFormat:@"yyyy-MM-dd' 06:00AM +0000'"]; // set the morning date here 
NSString *_morningDateString = [_dateFormatter stringFromDate:_currentDate]; 
[_dateFormatter setDateFormat:@"yyyy-MM-dd' 06:00PM +0000'"]; // set the evening date here 
NSString *_eveningDateString = [_dateFormatter stringFromDate:_currentDate]; 

[_dateFormatter setDateFormat:@"yyyy-MM-dd hh:mma zzz"]; 
NSDate *_morningDate = [_dateFormatter dateFromString:_morningDateString]; 
NSDate *_eveningDate = [_dateFormatter dateFromString:_eveningDateString]; 

NSTimeInterval _intervalToMorningDate = [_morningDate timeIntervalSinceDate:_currentDate]; 
NSTimeInterval _intervalToEveningDate = [_eveningDate timeIntervalSinceDate:_currentDate]; 

if (_intervalToMorningDate > 0) { 
    // now it is night 
    self.bgImage.image = [UIImage imageNamed:@"main_bg.png"]; 
    [self performSelector:@selector(replaceTheBackgoundForMorning) withObject:nil afterDelay:_intervalToMorningDate]; 
} else { 
    // now it is daytime 
    self.bgImage.image = [UIImage imageNamed:@"daylight.png"]; 
    [self performSelector:@selector(replaceTheBackgoundForEvening) withObject:nil afterDelay:_intervalToEveningDate]; 
} 
-(void)replaceTheBackgoundForMorning { 
// reaplce the backgound here 
self.bgImage.image = [UIImage imageNamed:@"daylight.png"]; 
} 

- (void)replaceTheBackgoundForEvening { 
// reaplce the backgoung here 
self.bgImage.image = [UIImage imageNamed:@"main_bg.png"]; 
} 

Answer 1

を使用してみてくださいNSDateComponents

以下のような

NSDateComponents *components = [[NSCalendar currentCalendar] components:NSCalendarUnitHour | NSCalendarUnitMinute | NSCalendarUnitSecond fromDate:[NSDate date]]; 
NSInteger nowHour = [components hour]; 
NSInteger nowMinute = [components minute]; 
NSInteger nowSecond = [components second]; 

if (nowHour < 6 || (nowHour > 18 || (nowHour == 18 && (nowMinute > 0 || nowSecond > 0)))) { 
    // Time is 6pm to 6am 
} 
else{ 
    // Time is 6am to 6pm