Question

如何在ios sdk中获取当月所有星期一的所有日期？

例如，我希望所有星期一的日期发生在2015年1月

下面的代码给出了nsdate的月，日和年。但是现在我想要那个月的工作日（星期一）的nsdate。

NSDate *currentDate = [NSDate date];
NSCalendar* calendar = [NSCalendar currentCalendar];
NSDateComponents* components = [calendar components:NSYearCalendarUnit|NSMonthCalendarUnit|NSDayCalendarUnit fromDate:currentDate]; // Get necessary date components

 [components month]; //gives you month
 [components day]; //gives you day
 [components year]; // gives you year

Answer 1

//Set Wantedday here with sun=1 ..... sat=7;
NSInteger wantedWeekDay = 2; //for monday

//set current date here
NSDate *currentDate = [NSDate date];

//get calender
NSCalendar *gregorianCalendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];

// Start out by getting just the year, month and day components of the current date.
NSDateComponents *components = [gregorianCalendar components:NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSCalendarUnitWeekday fromDate:currentDate];
// Change the Day component to 1 (for the first day of the month), and zero out the time components.
[components setDay:1];

[components setHour:0];
[components setMinute:0];
[components setSecond:0];

//get first day of current month
NSDate *firstDateOfCurMonth = [gregorianCalendar dateFromComponents:components];

//create new component to get weekday of first date
NSDateComponents *newcomponents = [gregorianCalendar components:NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSCalendarUnitWeekday fromDate:firstDateOfCurMonth];
NSInteger firstDateWeekDay = newcomponents.weekday;
NSLog(@"weekday : %li",(long)firstDateWeekDay);

//get last month date
NSInteger curMonth = newcomponents.month;
[newcomponents setMonth:curMonth+1];

NSDate * templastDateOfCurMonth = [[gregorianCalendar dateFromComponents:newcomponents] dateByAddingTimeInterval: -1]; // One second before the start of next month

NSDateComponents *lastcomponents = [gregorianCalendar components:NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSCalendarUnitWeekday fromDate:templastDateOfCurMonth];

[lastcomponents setHour:0];
[lastcomponents setMinute:0];
[lastcomponents setSecond:0];

NSDate *lastDateOfCurMonth = [gregorianCalendar dateFromComponents:lastcomponents];

NSLog(@"%@",lastDateOfCurMonth);

NSMutableArray *mutArrDates = [NSMutableArray array];

NSDateComponents *dayDifference = [NSDateComponents new];
[dayDifference setCalendar:gregorianCalendar];

//get wanted weekday date
NSDate *firstWeekDateOfCurMonth = nil;
if (wantedWeekDay == firstDateWeekDay) {
    firstWeekDateOfCurMonth = firstDateOfCurMonth;
}
else
{
    NSInteger day = wantedWeekDay - firstDateWeekDay;
    if (day < 0)
        day += 7;
    ++day;
    [components setDay:day];

    firstWeekDateOfCurMonth = [gregorianCalendar dateFromComponents:components];
}

NSLog(@"%@",firstWeekDateOfCurMonth);

NSUInteger weekOffset = 0;
NSDate *nextDate = firstWeekDateOfCurMonth;

do {
    [mutArrDates addObject:nextDate];
    [dayDifference setWeekOfYear:++weekOffset];
    NSDate *date = [gregorianCalendar dateByAddingComponents:dayDifference toDate:firstWeekDateOfCurMonth options:0];
    nextDate = date;
} while([nextDate compare:lastDateOfCurMonth] == NSOrderedAscending || [nextDate compare:lastDateOfCurMonth] == NSOrderedSame);

NSLog(@"%@",mutArrDates);

Answer 2

基本步骤

为该月的第一天（例如，2015年1月1日）创建一个NSDate对象
确定该日期的星期几
抵消您感兴趣的一周中某一天
在您到达月末之前添加7

这是一个如何做到这一点的例子

- (NSArray *) datesForWeekday:(NSInteger)weekday forMonth:(NSInteger)month andYear:(NSInteger)year
{
    unsigned int units = NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay
                        | NSCalendarUnitWeekday;
    // Step 1. create an NSDate for the first of the month
    NSDate *date = [self dateWithMonth:month day:1 andYear:year];

    // Step 2. determine the day of the week (1=Sunday, 2=Monday, ..., 7=Saturday
    NSDateComponents *comps = [[NSCalendar currentCalendar] components:units fromDate:date];
    NSInteger firstDayOfMonth = [comps weekday];

    // Step 3. offset so the day is the day of the week you are interested in
    NSInteger day = weekday - firstDayOfMonth;
    if (day < 0)
        day += 7;
    ++day;

    NSMutableArray *array = [NSMutableArray new];

    NSUInteger numberOfDaysInMonth = [self numberOfDaysWithDate:date];
    // Step 4. add 7 to the day until we reach the end of the month
    do {
        // Add NSDate object to array
        [array addObject:[self dateWithMonth:month day:day andYear:year]];

        // or you can optionally add just the day to the array
        // [array addObject:@(day)];

        day += 7;
    } while (day <= numberOfDaysInMonth);
    return array;
}

// Returns an NSDate object for the specified month, day, and year
- (NSDate *) dateWithMonth:(NSInteger)month day:(NSInteger)day andYear:(NSInteger)year
{
    NSDateComponents *dateComps = [[NSDateComponents alloc] init];
    [dateComps setDay:day];
    [dateComps setMonth:month];
    [dateComps setYear:year];
    [dateComps setHour:0];
    [dateComps setMinute:0];
    return [[NSCalendar currentCalendar] dateFromComponents:dateComps];
}

// Determines the number of days in the month for specified date
- (NSUInteger) numberOfDaysWithDate:(NSDate *)date
{
    NSRange days = [[NSCalendar currentCalendar] rangeOfUnit:NSCalendarUnitDay
                           inUnit:NSCalendarUnitMonth
                          forDate:date];
    return days.length;
}

以下是2015年1月查找所有星期一的示例

NSArray *dates = [self datesForWeekday:2 forMonth:1 andYear:2015];

或2018年12月的所有星期三

NSArray *dates = [self datesForWeekday:4 forMonth:12 andYear:2018];

或当月的所有星期一

NSDate *date = [NSDate date];
NSDateComponents *comps = [[NSCalendar currentCalendar] components:units fromDate:date];
NSArray *dates = [self datesForWeekday:2 forMonth:[comps month] andYear:[comps year]];

Answer 3

使用(NS)Calendar和NSCalendarUnitWeekdayOrdinal的{{1}}组件的简单解决方案。

获取当前日期(NS)DateComponents，year和month的组件。然后循环获取所有顺序工作日，直到月份部分超过当前月份为止

Objective-C：

weekdayOrdinal

快捷键：

- (NSArray<NSDate *> *)datesOfCurrentMonthWith:(NSInteger)weekday {

    NSCalendar *calendar = [NSCalendar currentCalendar];
    NSDateComponents *components = [calendar components:NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitWeekdayOrdinal  fromDate:[NSDate date]];
    components.weekday = 1;
    NSMutableArray<NSDate *> *result = [NSMutableArray array];

    for (NSInteger ordinal = 1; ordinal < 6; ordinal++) { // maximum 5 occurrences
        components.weekdayOrdinal = ordinal;
        NSDate *date = [calendar dateFromComponents:components];
        if ([calendar component:NSCalendarUnitMonth fromDate:date] != components.month) { break; }
        [result addObject:[calendar dateFromComponents: components]];
    }
    return [result copy];
}

Answer 4

只是通过你星期一得到的所有月份日期！我已经创建了一个例子，它在当前日期工作正常！

在viewDidLoad

中

NSDate *dt = [NSDate date];
NSCalendar *gregorian = [NSCalendar calendarWithIdentifier:NSCalendarIdentifierGregorian];
NSDateComponents *comp = [gregorian components: NSCalendarUnitEra |NSCalendarUnitYear | NSCalendarUnitMonth |NSCalendarUnitDay  fromDate:dt];

NSRange days = [gregorian rangeOfUnit:NSCalendarUnitDay
                       inUnit:NSCalendarUnitMonth
                      forDate:dt];

for (int i=1; i<days.length+1; i++)
{
    comp.day = i;
    if([self isMonday:[gregorian dateFromComponents:comp]])
    {
        NSLog(@"Monday %@",[gregorian dateFromComponents:comp]);
    }
}

-(BOOL)isTodayMonday:(NSDate*)dt
{
    BOOL isMonday;
    NSDateFormatter *datef = [[NSDateFormatter alloc]init];
    datef.dateFormat = @"EEEE";
    NSString *strDate = [datef stringFromDate:dt];
    if([strDate isEqualToString:@"Monday"])
    {
       NSLog(@"monday date %@",dt);
       isMonday = YES;
    }
    else
    {
        isMonday = NO;    
    }
    return isMonday;
}

您可以参考here

获取ios sdk中当月星期一的所有日期

4 个答案: