objective-c日历可选日期实例

【核心代码】

//
//  ViewController.m
//  DateDemo
//
//  Created by healthmanage on 16/7/8.
//  Copyright © 2016年 healthmanager. All rights reserved.
//

#import "ViewController.h"

@interface ViewController ()<UICollectionViewDelegate,UICollectionViewDataSource>

@property(nonatomic,strong)UILabel *yearAndMonthLabel;//年月UILabel

@property(nonatomic,strong)UICollectionView *collectionV;

@property(nonatomic,assign)CGFloat itemWidthF;//item的宽
@property(nonatomic,assign)CGFloat itemHeightF;//item的高

@property(nonatomic,strong)NSMutableArray *daysArray;//用来记录不同月份选中的日子
@property(nonatomic,assign)NSInteger weekFirstDayInt;//当前月的第一天是星期几
@property(nonatomic,copy)NSString *monthStr;//某月
@property(nonatomic,copy)NSString *todayMonthStr;//当天年月
@property(nonatomic,assign)NSInteger todayDayInt;//当天日

@end

#define f_Device_w         [UIScreen mainScreen].bounds.size.width//屏幕宽度
#define Weekdays @[@"日", @"一", @"二", @"三", @"四", @"五", @"六"]

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    _itemWidthF = f_Device_w/7;
    _itemHeightF = 40;
    
    _daysArray = [NSMutableArray new];
    //获取当前日期
    NSString *dateStr = [self getCurMonthday];
    //获取当前年月
    _todayMonthStr = [dateStr substringToIndex:6];
    //获取当前日
    _todayDayInt = [[dateStr substringFromIndex:6] intValue];
    //获取当前月的第一天是星期几
    _weekFirstDayInt = [self weekdayOfFirstDayInDate:_todayMonthStr];
    //获取年月
    _monthStr = _todayMonthStr;
    //显示头视图年月
    [self showYearAndMonth];
    //显示日历
    [self showCollectionView];
}
#pragma mark --- 创建头视图左右按钮
-(void)showYearAndMonth
{
    //设置头背景
    UIView *headView = [[UIView alloc] initWithFrame:CGRectMake(0, 50, f_Device_w, 75)];
    headView.backgroundColor = [UIColor lightGrayColor];
    [self.view addSubview:headView];
    //创建左边按钮
    UIButton *leftBtn = [UIButton buttonWithType:UIButtonTypeCustom];
    leftBtn.frame = CGRectMake(10, 3, 30, 39);
    [leftBtn setBackgroundImage:[UIImage imageNamed:@"left.png"] forState:UIControlStateNormal];
    [headView addSubview:leftBtn];
    [leftBtn addTarget:self action:@selector(leftBtnClick:) forControlEvents:UIControlEventTouchUpInside];
    //创建年月显示UILabel
    _yearAndMonthLabel = [[UILabel alloc] initWithFrame:CGRectMake(50, 3, f_Device_w-50*2, 39)];
    _yearAndMonthLabel.text = [NSString stringWithFormat:@"%@年%@月",[_todayMonthStr substringWithRange:NSMakeRange(0, 4)],[_todayMonthStr substringWithRange:NSMakeRange(4, 2)]];
    _yearAndMonthLabel.textAlignment = NSTextAlignmentCenter;
    _yearAndMonthLabel.textColor = [UIColor lightGrayColor];
    _yearAndMonthLabel.backgroundColor = [UIColor whiteColor];
    [headView addSubview:_yearAndMonthLabel];
    //创建右边按钮
    UIButton *rightBtn = [UIButton buttonWithType:UIButtonTypeCustom];
    rightBtn.frame = CGRectMake(f_Device_w-40, 3, 30, 39);
    [rightBtn setBackgroundImage:[UIImage imageNamed:@"right.png"] forState:UIControlStateNormal];
    [headView addSubview:rightBtn];
    [rightBtn addTarget:self action:@selector(rightBtnClick:) forControlEvents:UIControlEventTouchUpInside];
    //创建星期文字
    for (int i = 0; i < Weekdays.count; i   )
    {
        UILabel *weekdayLabel = [[UILabel alloc] initWithFrame:CGRectMake(_itemWidthF*i, 45, _itemWidthF, 29)];
        weekdayLabel.textAlignment = NSTextAlignmentCenter;
        weekdayLabel.text = Weekdays[i];
        weekdayLabel.textColor = [UIColor darkGrayColor];
        weekdayLabel.backgroundColor = [UIColor whiteColor];
        [headView addSubview:weekdayLabel];
    }
    //分割线
    UIView *lineView = [[UIView alloc] initWithFrame:CGRectMake(0, 74, f_Device_w, 1)];
    lineView.backgroundColor = [UIColor blackColor];
    [headView addSubview:lineView];
    
}
#pragma mark --- 显示日历UICollectionView
-(void)showCollectionView
{
    //创建UICollectionView
    UICollectionViewFlowLayout *flowLayout = [UICollectionViewFlowLayout new];
    flowLayout.sectionInset = UIEdgeInsetsZero;//每个分区插入间隔为0
    flowLayout.itemSize = CGSizeMake(_itemWidthF, _itemHeightF);//item的大小
    flowLayout.minimumLineSpacing = 0;//最小行间距
    flowLayout.minimumInteritemSpacing = 0;//最小列间距
    
    _collectionV = [[UICollectionView alloc] initWithFrame:CGRectMake(0, 125, f_Device_w, 240) collectionViewLayout:flowLayout];
    _collectionV.delegate = self;
    _collectionV.dataSource = self;
    _collectionV.backgroundColor = [UIColor whiteColor];
    [self.view addSubview:_collectionV];
    //注册Cell
    [_collectionV registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:@"cell"];
}
#pragma mark --- 左按钮点击事件
-(void)leftBtnClick:(UIButton *)buttonN
{
    //NSLog(@"点击了左侧按钮。。。。");
    //设置上一个年月
    NSString *lastMonth = [self completeMonth:_monthStr gap:-1];
    //判断当天日期之前的时间不能选择
    if ([lastMonth compare:_todayMonthStr options:NSNumericSearch] != NSOrderedAscending)
    {
        _monthStr = lastMonth;
        _yearAndMonthLabel.text = [NSString stringWithFormat:@"%@年%@月",[lastMonth substringWithRange:NSMakeRange(0, 4)],[lastMonth substringWithRange:NSMakeRange(4, 2)]];
        //获取当前月的第一天是星期几
        _weekFirstDayInt = [self weekdayOfFirstDayInDate:_monthStr];
        
        [_collectionV removeFromSuperview];
        
        //替换日历
        [self showCollectionView];
    }
}
#pragma mark --- 右按钮点击事件
-(void)rightBtnClick:(UIButton *)buttonN
{
    //NSLog(@"点击了右侧按钮。。。。");
    //设置下一个月日期
    NSString *nextMonth = [self completeMonth:_monthStr gap:1];
    _monthStr = nextMonth;
    _yearAndMonthLabel.text = [NSString stringWithFormat:@"%@年%@月",[nextMonth substringWithRange:NSMakeRange(0, 4)],[nextMonth substringWithRange:NSMakeRange(4, 2)]];
    //获取当前月的第一天是星期几
    _weekFirstDayInt = [self weekdayOfFirstDayInDate:_monthStr];
    
    [_collectionV removeFromSuperview];
    
    //替换日历
    [self showCollectionView];
}
#pragma mark -- 根据年月获取当前月的第一天是星期几
- (NSInteger)weekdayOfFirstDayInDate:(NSString *)curYearMonth {
    NSDateFormatter *dateFormatter = [NSDateFormatter new];
    [dateFormatter setDateFormat:@"yyyyMM"];
    NSDate *date = [dateFormatter dateFromString:curYearMonth];
    NSCalendar *calendar = [NSCalendar currentCalendar];
    [calendar setFirstWeekday:1];
    NSDateComponents *components = [calendar components:NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay fromDate:date];
    [components setDay:1];
    NSDate *firstDate = [calendar dateFromComponents:components];
    NSDateComponents *firstComponents = [calendar components:NSCalendarUnitWeekday fromDate:firstDate];
    return firstComponents.weekday-1;
}
#pragma mark --- 获取当前年月日
-(NSString *)getCurMonthday{
    NSDate *today = [NSDate date];
    NSDateFormatter *dateFormatter = [NSDateFormatter new];
    [dateFormatter setDateFormat:@"yyyyMMdd"];
    NSString *strDate = [dateFormatter stringFromDate:today];
    return strDate;
}
#pragma mark --- 根据年月获取当前月的总天数
-(NSInteger)totalDaysInMothOfDate:(NSString *)curYearMonth
{
    NSDateFormatter *dateFormatter = [NSDateFormatter new];
    [dateFormatter setDateFormat:@"yyyyMM"];//日期形式
    NSDate *dateE = [dateFormatter dateFromString:curYearMonth];//将NSString转换成NSDate类型
    NSRange rangeE = [[NSCalendar currentCalendar] rangeOfUnit:NSCalendarUnitDay inUnit:NSCalendarUnitMonth forDate:dateE];//参数一：最小单元，参数二：在哪个单元中，参数三：传入日期
    return rangeE.length;
}
#pragma mark --- 根据传值计算间隔月份:传入负值，表示之前的月份，传入正值，表示之后的月份
-(NSString *)completeMonth:(NSString *)month gap:(int) gap{
    NSDateFormatter *dateFormatter = [NSDateFormatter new];
    [dateFormatter setDateFormat:@"yyyyMM"];
    NSDate *monthDate = [dateFormatter dateFromString:month];
    NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];
    NSDateComponents *adcomps = [[NSDateComponents alloc] init];
    [adcomps setMonth:gap];
    NSDate *newdate = [calendar dateByAddingComponents:adcomps toDate:monthDate options:0];
    return [dateFormatter stringFromDate:newdate];
}

#pragma mark --- UICollectionViewDelegate and DataSource
-(NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
    return _weekFirstDayInt [self totalDaysInMothOfDate:_monthStr];
}
-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
    UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"cell" forIndexPath:indexPath];
    UILabel *nameLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, _itemWidthF, _itemWidthF)];
    nameLabel.backgroundColor = [UIColor clearColor];
    nameLabel.textAlignment = NSTextAlignmentCenter;
    nameLabel.font = [UIFont systemFontOfSize:15];
    nameLabel.tag = 100;
    [cell addSubview:nameLabel];
    
    cell.tag = 1;
    
    //1.判断这个月的一号是星期几，并对应显示
    if (indexPath.row >= _weekFirstDayInt)
    {
        int dayInt = indexPath.row 1-_weekFirstDayInt;
        nameLabel.text = [NSString stringWithFormat:@"%d",dayInt];
        //2.根据不同条件显示不同的颜色
        //当显示的是未来的月份时，字体显示黑色
        if ([_monthStr compare:_todayMonthStr options:NSNumericSearch] == NSOrderedDescending)
        {
            nameLabel.textColor = [UIColor blackColor];
        }
        //当显示的是当前月份时
        else if([_monthStr compare:_todayMonthStr options:NSNumericSearch] == NSOrderedSame)
        {
            //在当前日期之前的时间，字体显示为浅灰色
            if (dayInt < _todayDayInt)
            {
                nameLabel.textColor = [UIColor lightGrayColor];
            }
            //当前日期，字体显示为红色
            else if(dayInt == _todayDayInt)
            {
                nameLabel.textColor = [UIColor redColor];
            }
            //当前日期之后的时间，字体显示为黑色
            else
            {
                nameLabel.textColor = [UIColor blackColor];
            }
        }
        //当前日期之前的时间，字体显示为浅灰色
        else
        {
            nameLabel.textColor = [UIColor lightGrayColor];
        }
    }
    
    //将已经选择好的进行显示
    if (_daysArray.count > 0)
    {
        for (int i = 0; i < _daysArray.count; i   )
        {
            //当前年月
            NSString *monthStr = [_daysArray[i] substringToIndex:6];
            if ([monthStr isEqualToString:_monthStr])
            {
                //如果与当前月一样，显示某日选中的情况
                int dayInt = [[_daysArray[i] substringFromIndex:6] intValue];
                if (dayInt == indexPath.row 1-_weekFirstDayInt)
                {
                    cell.backgroundColor = [UIColor greenColor];
                    nameLabel.textColor = [UIColor whiteColor];
                    cell.tag = 2;
                }
            }
        }
    }
    
    return cell;
}
-(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
    //标记
    BOOL flag = NO;//当前日期前的时间，表示不可选的
    if ([_monthStr compare:_todayMonthStr options:NSNumericSearch]==NSOrderedDescending || [_monthStr compare:_todayMonthStr options:NSNumericSearch]==NSOrderedSame)
    {
        flag = YES;//表示可选的时间
    }
    //选中的显示不同的颜色,并且记录各个月份选中的日子
    UICollectionViewCell *cell = [collectionView cellForItemAtIndexPath:indexPath];
    UILabel *dayLabel = (UILabel *)[cell viewWithTag:100];
    if (flag)
    {
        NSString *dayStr = dayLabel.text;
        if ([dayStr intValue] < 10)
        {
            dayStr = [NSString stringWithFormat:@"0%@",dayStr];
        }
        //取消选中
        if (cell.tag != 1)
        {
            cell.backgroundColor = [UIColor clearColor];
            dayLabel.textColor = [UIColor blackColor];
            cell.tag = 1;
            [_daysArray removeObject:[NSString stringWithFormat:@"%@%@",_monthStr,dayStr]];
        }
        else
        {
            //选中
            cell.backgroundColor = [UIColor greenColor];
            dayLabel.textColor = [UIColor whiteColor];
            cell.tag = 2;
            
            [_daysArray addObject:[NSString stringWithFormat:@"%@%@",_monthStr,dayStr]];
        }
        
    }
}


- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end