区域格式在iOS中无法正常工作

Question

对于手机设置，我意识到当我的用户使用英国的地区格式时，它将周范围变为2013年11月10日 - 2013年11月16日。但对于美国，它显示正确的周范围，即2013年11月3日 - 2013年11月9日。

有没有人知道以编程方式解决的正确方法？

这是我的代码......

NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDate *currentWeekFirstDay = [CWHelperTime getFirstDayOfWeek:[NSDate date]];

if( !self.weekStartDate ){

    self.weekStartDate = currentWeekFirstDay;

} else {

    NSDateComponents *prevWeekStartComponents = [gregorian components:NSDayCalendarUnit fromDate:self.weekStartDate];

    if( self.currentWeekIndex < weekIndex )
        prevWeekStartComponents.day = +7;
    else
        prevWeekStartComponents.day = -7;

    self.currentWeekIndex = weekIndex;        
    self.weekStartDate = [gregorian dateByAddingComponents:prevWeekStartComponents toDate:self.weekStartDate options:0];
}

NSDateComponents *weekEndComponents = [gregorian components:NSDayCalendarUnit fromDate:self.weekStartDate];
weekEndComponents.day = +6;
self.weekEndDate = [gregorian dateByAddingComponents:weekEndComponents toDate:self.weekStartDate options:0];

这是针对getFirstDayOfWeek

的

[NSTimeZone setDefaultTimeZone:[NSTimeZone timeZoneWithName:@"Asia/Singapore"]];
NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *components = [calendar components:NSYearCalendarUnit|NSMonthCalendarUnit|NSWeekCalendarUnit|NSWeekdayCalendarUnit fromDate:date];

// Find Sunday for the given date
components = [calendar components:NSYearCalendarUnit|NSMonthCalendarUnit|NSWeekCalendarUnit|NSWeekdayCalendarUnit fromDate:date];
[components setWeekday:1]; // 1 == Sunday, 7 == Saturday
[components setWeek:[components week]];

return [calendar dateFromComponents:components];