因为程序要求要插入一个日历控件,该空间的要求是从当天开始及以后的六个月内的日历,上网查资料基本上都说只要获取两个条件(当月第一天周几和本月一共有多少天)就可以实现一个简单的日历,剩下的靠自己的简单逻辑就OK了,下面开始自己从开始到完成的整个过程
1.首先做NSDate类目,扩展一些方法让日期之间转换更加方便
#import <Foundation/Foundation.h>
@interface NSDate (LYWCalendar)
#pragma mark - 获取日
- (NSInteger)day:(NSDate *)date;
#pragma mark - 获取月
- (NSInteger)month:(NSDate *)date;
#pragma mark - 获取年
- (NSInteger)year:(NSDate *)date;
#pragma mark - 获取当月第一天周几
- (NSInteger)firstWeekdayInThisMonth:(NSDate *)date;
#pragma mark - 获取当前月有多少天
- (NSInteger)totaldaysInMonth:(NSDate *)date;
@end
下面一一实现这些方法
#import "NSDate+LYWCalendar.h"
@implementation NSDate (LYWCalendar)
/**
*实现部分
*/
#pragma mark -- 获取日
- (NSInteger)day:(NSDate *)date{
NSDateComponents *components = [[NSCalendar currentCalendar] components:(NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay) fromDate:date];
return components.day;
}
#pragma mark -- 获取月
- (NSInteger)month:(NSDate *)date{
NSDateComponents *components = [[NSCalendar currentCalendar] components:(NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay) fromDate:date];
return components.month;
}
#pragma mark -- 获取年
- (NSInteger)year:(NSDate *)date{
NSDateComponents *components = [[NSCalendar currentCalendar] components:(NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay) fromDate:date];
return components.year;
}
#pragma mark -- 获得当前月份第一天星期几
- (NSInteger)firstWeekdayInThisMonth:(NSDate *)date{
NSCalendar *calendar = [NSCalendar currentCalendar];
//设置每周的第一天从周几开始,默认为1,从周日开始
[calendar setFirstWeekday:1];//1.Sun. 2.Mon. 3.Thes. 4.Wed. 5.Thur. 6.Fri. 7.Sat.
NSDateComponents *comp = [calendar components:(NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay) fromDate:date];
[comp setDay:1];
NSDate *firstDayOfMonthDate = [calendar dateFromComponents:comp];
NSUInteger firstWeekday = [calendar ordinalityOfUnit:NSCalendarUnitWeekday inUnit:NSCalendarUnitWeekOfMonth forDate:firstDayOfMonthDate];
//若设置从周日开始算起则需要减一,若从周一开始算起则不需要减
return firstWeekday - 1;
}
#pragma mark -- 获取当前月共有多少天
- (NSInteger)totaldaysInMonth:(NSDate *)date{
NSRange daysInLastMonth = [[NSCalendar currentCalendar] rangeOfUnit:NSCalendarUnitDay inUnit:NSCalendarUnitMonth forDate:date];
return daysInLastMonth.length;
}
接下来就要写逻辑部分了,在ViewController里面实现,先说思想,首先想到的是用collectionView,但是每个月天数不一样在日历中的显示就不一样,有时候有五行有时候有六行,既然要用自动填充就必须考虑到这一点,下面是代码实现
