iPhone NSDate例如。下週五

Question

我想創建一個函數，導致下週五的日期，但我沒有計劃如何去做。有沒有人給我一個好的提示？

Answer 1

E.g.使用NSDate獲取當前日期，然後使用NSCalendar的'components> fromDate：'獲取NSDateComponents，然後將時間差添加到下一個星期五，並創建一個新的NSDate，Bob's是您的叔叔。

Answer 2

這是我的解決方案，只是爲了提醒你，星期六是星期五展示之前。 歡呼所有

NSDate *today = [[NSDate alloc] init]; 
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar]; 

NSDateComponents *weekdayComponents = [gregorian components:NSWeekdayCalendarUnit fromDate:today]; 
int weekday = [weekdayComponents weekday]; 


int iOffsetToFryday = -weekday + 6; 
weekdayComponents.weekday = iOffsetToFryday; 

NSDate *nextFriday = [[NSCalendar currentCalendar] dateByAddingComponents:weekdayComponents toDate:today options:0]; 

Answer 3

這裏是獲取未來5日在公曆我工作的解決方案：

self.nextBeginDates = [NSMutableArray array]; 

NSDateComponents *weekdayComponents = [[NSCalendar currentCalendar] components:NSWeekdayCalendarUnit fromDate:[NSDate date]]; 
int currentWeekday = [weekdayComponents weekday]; //[1;7] ... 1 is sunday, 7 is saturday in gregorian calendar 

NSDateComponents *comp = [[NSDateComponents alloc] init]; 
[comp setDay:8 - currentWeekday]; // add some days so it will become sunday 

// build weeks array 
int weeksCount = 5; 
for (int i = 0; i < weeksCount; i++) { 
    [comp setWeek:i]; // add weeks 

    [nextBeginDates addObject:[[NSCalendar currentCalendar] dateByAddingComponents:comp toDate:[NSDate date] options:0]]; 
} 
[comp release]; 

Answer 4

這應該工作

+ (NSDate *) dateForNextWeekday: (NSInteger)weekday { 

NSDate *today = [[NSDate alloc] init]; 
NSCalendar *gregorian = [[NSCalendar alloc] 
         initWithCalendarIdentifier:NSGregorianCalendar]; 

// Get the weekday component of the current date 
NSDateComponents *weekdayComponents = [gregorian components:NSWeekdayCalendarUnit 
                fromDate:today]; 

/* 
Add components to get to the weekday we want 
*/ 
NSDateComponents *componentsToSubtract = [[NSDateComponents alloc] init]; 
NSInteger dif = weekday-weekdayComponents.weekday; 
if (dif<=0) dif += 7; 
[componentsToSubtract setDay:dif]; 

NSDate *beginningOfWeek = [gregorian dateByAddingComponents:componentsToSubtract 
                toDate:today options:0]; 

return beginningOfWeek; 

}

Answer 5

保持它簡單，安全，可讀！ （.... KISSAR？）

#define FRIDAY 6 

NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar]; 
NSDateComponents *dayComponent = [[NSDateComponents alloc] init]; 
dayComponent.day = 1; 

NSDate *nextFriday = [NSDate date]; 
NSInteger iWeekday = [[gregorian components:NSWeekdayCalendarUnit fromDate:nextFriday] weekday]; 

while (iWeekday != FRIDAY) { 
    nextFriday = [gregorian dateByAddingComponents:dayComponent toDate:nextFriday options:0]; 
    iWeekday = [[gregorian components:NSWeekdayCalendarUnit fromDate:nextFriday] weekday]; 
} 

現在nextFriday有你的約會。

希望這會有所幫助！

編輯 請注意，如果當前日期已經是星期五，它將返回，而不是下一個星期五。如果這是不可取的，只需在一天之後啓動nextFriday（所以如果當前日期是星期五，它將在星期六開始，迫使下一個星期五。如果當前日期是星期四，您將自動在下個星期五不需要循環）。