2个NSDates

Question

假设我们使用的是公历日历系统之间的号码周末，什么是制定出有两个NSDate对象之间发生这周末的数目最好的方法是什么？

我目前的做法是计算两个NSDate之间的天数，然后除以7和floor()结果。这给了我几周的时间，结果是周末的数量。因为如果一周尚未完成（并且该部门有剩余部分），我们就会得到结果，它会忽略该结果并只考虑已经过去的整周。

改善和稳健性的任何建议，将不胜感激。

Answer 1

当你注意你的解决方案可能会返回一个值小于周末的实际数量。

若要计算可能的额外周末，如果除以7后的总天数的剩余天数大于0，则比较周日数（例如NSDateComponents的weekday-这是周日的7到周六的1）开始和结束日期。如果结束的周日数小于开始日期，那么必须有一个周末之间（周六/周日的变化计算为周末 - 如果您觉得合适的话进行调整）。

HTH

Answer 2

这里有一个快速的实现：

NSCalendar *cal = [NSCalendar currentCalendar]; 
NSDate *endDate = [NSDate dateWithTimeIntervalSinceNow:1209600]; 
NSDate *startDate = [NSDate date]; 
NSDateComponents *comps = [cal components:NSCalendarUnitWeekday | NSCalendarUnitDay fromDate:startDate toDate:endDate options:kNilOptions]; 
NSDateFormatter *fmt = [[NSDateFormatter alloc] init]; 
[fmt setLocale:[NSLocale localeWithLocaleIdentifier:@"en_US"]]; 
[fmt setDateFormat:@"EEEE"]; 
NSArray *weekend = [fmt weekdaySymbols]; 
NSPredicate *pred = [NSPredicate predicateWithFormat:@"SELF == 'Saturday' || SELF == 'Sunday'"]; 
NSArray *weekendArr = [weekend filteredArrayUsingPredicate:pred]; 
NSString *weekendsStr = [weekendArr componentsJoinedByString:@""]; 
NSDateComponents *compsWithDay = [[NSDateComponents alloc] init]; 
[compsWithDay setDay:1]; 
NSString *dayNameStr = [fmt stringFromDate:startDate]; 
NSUInteger count = 0; 
if ([weekendsStr rangeOfString:dayNameStr].location != NSNotFound) { 
    count++; 
} 
for (int i = 0; i < comps.day; i++) { 
    startDate = [cal dateByAddingComponents:compsWithDay toDate:startDate options:kNilOptions]; 
    dayNameStr = [fmt stringFromDate:startDate]; 
    if ([weekendsStr rangeOfString:dayNameStr].location != NSNotFound) { 
    count++; 
    } 
} 

注：

1. 此代码应该只与ARC启用
2. 也许有冗余使用，不能看它现在。但代码正常工作。

Answer 3

尝试这样，代码的描述是否有意见： -

//Assuming this is your dates where you need to determine the weekend in between two dates 
NSString *strDate1=@"10-01-2014"; 
NSString *strDate2=@"19-01-2014"; 
NSDateFormatter *format=[[NSDateFormatter alloc]init]; 
[format setDateFormat:@"dd-MM-yyyy"]; 
NSDate *dt1=[format dateFromString:strDate1]; 
NSDate *dt2=[format dateFromString:strDate2]; 

//Now finding the days between two dates 
NSUInteger units = NSYearCalendarUnit|NSMonthCalendarUnit|NSDayCalendarUnit|NSWeekdayCalendarUnit; 
NSCalendar *cal = [[[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar] autorelease]; 
NSDateComponents *com=[cal components:units fromDate:dt1 toDate:dt2 options:0]; 
NSInteger day1=[com day]; 
int i=0; 
int j=0; 


//Now calculating how many weekends(Sat, Sun) are there in the total number of days. 
for(i=0; i<=day1; i++) 
{ 
    com=[[NSDateComponents alloc]init]; 
    [com setDay:i]; 
    NSDate *newDate = [[NSCalendar currentCalendar] 
         dateByAddingComponents:com 
         toDate:dt1 options:0]; 
    [format setDateFormat:@"EEE"]; 
    NSString *satSun=[format stringFromDate:newDate]; 
    if ([satSun isEqualToString:@"Sat"] || [satSun isEqualToString:@"Sun"]) 
    { 
     j++; 

    } 
} 
     NSLog(@"Total number of weekends found= %d",j);