iSO简单的日历实现

简单的日历实现：其中firstDay_InMonth代表本月的第一天尾星期几 allDay_InMonth代表本月一共有几天

//星期

    NSArray *array = [NSArrayarrayWithObjects:@"日",@"一",@"二",@"三",@"四",@"五",@"六",nil];

    for (int i =0; i < 7; i++) {

        UILabel *label = [[UILabelalloc] initWithFrame:CGRectMake(WIDTH/7 * i,0, WIDTH/7,30)];

        label.textAlignment =NSTextAlignmentCenter;

        label.font = [UIFontsystemFontOfSize:13];

        label.textColor = [UIColordarkTextColor];

        label.text = array[i];

        [self.bagViewaddSubview:label];

    }

    

    //日期

    for (NSInteger i =self.firstDay_InMonth; i<self.allDay_InMonth+self.firstDay_InMonth; i++) {

        UIButton *button = [UIButtonbuttonWithType:UIButtonTypeSystem];

        [button setTitle:[[NSNumbernumberWithInteger:i-self.firstDay_InMonth+1]stringValue] forState:UIControlStateNormal];

        button.backgroundColor = [UIColorwhiteColor];

        [button setTitleColor:[UIColordarkGrayColor] forState:UIControlStateNormal];

        

        NSInteger n = i/7;

        button.frame = CGRectMake((i-n*7)*WIDTH/7+1, WIDTH/7*n+30+1, WIDTH/7-2, WIDTH/7-2);

        [self.bagViewaddSubview:button];

    }

}

//第一天是周几

- (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 *component = [calendarcomponents:(NSCalendarUnitYear |NSCalendarUnitMonth | NSCalendarUnitDay)fromDate:date];

    [component setDay:1];

    NSDate *firstDayOfMonthDate = [calendar dateFromComponents:component];

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

    return firstWeekDay - 1;

}

//当月总天数

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

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

    return daysInOfMonth.length;

}

//上个月

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

    NSDateComponents *dateComponents = [[NSDateComponentsalloc] init];

    dateComponents.month = -1;

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

    return newDate;

}

//下个月

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

    NSDateComponents *dateComponents = [[NSDateComponentsalloc] init];

    dateComponents.month = +1;

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

    return newDate;

}

//获取日

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

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

    return [components day];

}

//获取月

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

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

    return [components month];

}

//获取年

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

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

    return [components year];

}