给定周的第一个日期（NSDate）

Question

I have a week number in int and I want to get the first date( NSDate value ) of that week.

For an Example: First date ( sunday ) of the 21st week of 2011 is 2011-05-22

I'm trying with NSCalendar, NSDateComponents to achieve this. If anybody knows how to achieve this really appreciate your help.

Answer 1

Try something like:

NSDate *now = [NSDate date];
NSCalendar *gregorian = [[[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar] autorelease];
NSDateComponents *comp = [gregorian components:NSYearCalendarUnit fromDate:now];
[comp setWeekday:1];
[comp setWeek: 21];
NSDate *resultDate = [gregorian dateFromComponents:comp];