NSDate obtenir un jour spécifique de la semaine?

Question

J'espère que c'est juste une courbe d'apprentissage que je traverse.

Je crée une date arbitraire. Je veux trouver le samedi suivant le troisième vendredi.

NSLog(@"Date: %@", [date description]); 
    NSCalendar *calendar = [NSCalendar currentCalendar]; 
    NSTimeZone *zone = [NSTimeZone timeZoneWithName:@"EST"]; 
    [calendar setTimeZone:zone]; 
    NSDateComponents *components = [calendar components:(NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit) fromDate:date]; 
    [components setWeekday:6];  // 1 = Sunday ... 7 = Saturday 
    [components setWeekdayOrdinal:3]; // 3rd Friday 
    resultDate = [calendar dateFromComponents:components]; 
    NSLog(@"Date: %@", [resultDate description]); 

Et la sortie:

Date: 2010-11-01 05:00:00 GMT

Date: 2010-11-01 05:00:00 GMT

Pourquoi ? Comment puis-je réparer cela?

Answer 1

Modifier les composants:

(NSWeekdayCalendarUnit | NSYearCalendarUnit) 

Cela fonctionne:

NSDate *today = [[NSDate alloc] init]; 
NSLog([today description]); 

NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar]; 

NSDateComponents *weekdayComponents = [gregorian components:(NSWeekdayCalendarUnit | NSWeekdayOrdinalCalendarUnit) fromDate:today]; 

NSDateComponents *componentsToSubtract = [[NSDateComponents alloc] init]; 
[componentsToSubtract setDay: 0 - ([weekdayComponents weekday])]; 
[componentsToSubtract setWeekdayOrdinal:([weekdayComponents weekday] <= 6) ? 3 : 4]; 
//[componentsToSubtract setWeekdayOrdinal:3]; //old way - not perfect 

NSDate *saturday = [gregorian dateByAddingComponents:componentsToSubtract toDate:today options:0]; 
NSDateComponents *components = 
[gregorian components:(NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit) 
    fromDate: saturday]; 
saturday = [gregorian dateFromComponents:components]; 

NSLog([saturday description]); 

Hope this helps.

Answer 2

// Sunday = 1, Saturday = 7 

int weekday = [[[NSCalendar currentCalendar] components:NSWeekdayCalendarUnit fromDate: date] weekday];