iOS 日历

       这两天需要做一个日历，自己研究了一下写了一个简单的Demo版本出来供大家参考，纯代码写的

首先，日历我是用collection view写的，其次，我用的是自带的date属性来获取数据的

最主要的方法就是获取数据源，下面是我注释的基本数据源方法

#pragma mark -- date

//得到今天是几号

- (NSInteger)day:(NSDate *)date{

    NSDateComponents *components = [[NSCalendarcurrentCalendar]components:(NSCalendarUnitYear
|NSCalendarUnitMonth |NSCalendarUnitDay)
fromDate:date];

    return [componentsday];

}

//得到今天是几月

- (NSInteger)month:(NSDate *)date{

    NSDateComponents *components = [[NSCalendarcurrentCalendar]components:(NSCalendarUnitYear
|NSCalendarUnitMonth |NSCalendarUnitDay)
fromDate:date];

    return [componentsmonth];

}

//得到今年是几年

- (NSInteger)year:(NSDate *)date{

    NSDateComponents *components = [[NSCalendarcurrentCalendar]components:(NSCalendarUnitYear
|NSCalendarUnitMonth |NSCalendarUnitDay)
fromDate:date];

    return [componentsyear];

}

//第一周的第一天在什么位置

- (NSInteger)firstWeekdayInThisMonth:(NSDate *)date{

    NSCalendar *calendar = [NSCalendarcurrentCalendar];

    

    [calendar setFirstWeekday:1];//1.Sun. 2.Mon. 3.Thes. 4.Wed. 5.Thur.
6.Fri. 7.Sat.

    NSDateComponents *comp = [calendarcomponents:(NSCalendarUnitYear
|NSCalendarUnitMonth |
NSCalendarUnitDay) fromDate:date];

    [comp setDay:1];

    NSDate *firstDayOfMonthDate = [calendardateFromComponents:comp];

    

    NSUInteger firstWeekday = [calendarordinalityOfUnit:NSCalendarUnitWeekdayinUnit:NSCalendarUnitWeekOfMonthforDate:firstDayOfMonthDate];

    return firstWeekday -1;

}

//这个月有多少天

- (NSInteger)totaldaysInThisMonth:(NSDate *)date{

    NSRange totaldaysInMonth = [[NSCalendarcurrentCalendar]rangeOfUnit:NSCalendarUnitDayinUnit:NSCalendarUnitMonthforDate:date];

    return totaldaysInMonth.length;

}

//上个月的date数据（用于刷新）

- (NSDate *)lastMonth:(NSDate *)date{

    NSDateComponents *dateComponents = [[NSDateComponentsalloc]init];

    dateComponents.month = -1;

    NSDate *newDate = [[NSCalendarcurrentCalendar]dateByAddingComponents:dateComponentstoDate:dateoptions:0];

    return newDate;

}

//下个月的date数据（用于刷新）

- (NSDate*)nextMonth:(NSDate *)date{

    NSDateComponents *dateComponents = [[NSDateComponentsalloc]init];

    dateComponents.month = +1;

    NSDate *newDate = [[NSCalendarcurrentCalendar]dateByAddingComponents:dateComponentstoDate:dateoptions:0];

    return newDate;

}

看下效果

不好意思，上次传的没传上去，见谅,这次传上去了

我已经上传到git上面了：https://github.com/liuhugit/NewDate