比较符合项目需要，要做一个日历选择器，并且实现当前日期之后的时间不可选。网上找了一下，GitHub上的一个开源日历选择器CKCalendar比较符合项目需求。效果图如下：（很反感网上那些文章讲了半天连个效果图都没有，纯个人吐槽，勿喷~）

    刚开始对着CKCalendar的源码看来半天，还想着直接修改源码让当前日期之后的不可选，却忘了去测试作者提供的代理接口，真傻！

鼓捣半天后终于弄出来了，怕时间久了就忘了，还是做一下笔记：

当前日期之后不可选：

#pragma mark - CalendarPickerDelegate Method
- (BOOL)calendar:(CKCalendarView *)calendar willSelectDate:(NSDate *)date
{
    NSDate *now = [NSDate date];
    NSString *stringNow = [DATE_FORMATER stringFromDate:now];
    now = [DATE_FORMATER dateFromString:stringNow];
    NSString *selectedValue;
    if ([date compare:now] == NSOrderedSame ||[date compare:now] == NSOrderedAscending) {
        _calendarPickerVC.selectedDate = date;
        selectedValue = http://www.mamicode.com/[DATE_FORMATER stringFromDate:_calendarPickerVC.selectedDate];>

当前日期之前不可选：
#pragma mark - CalendarPickerDelegate Menthod
- (BOOL)calendar:(CKCalendarView *)calendar willSelectDate:(NSDate *)date
{
    NSDate *now = [NSDate date];
    NSString *stringNow = [DATE_FORMATER stringFromDate:now];
    now = [DATE_FORMATER dateFromString:stringNow];
    NSString *selectedValue;
    if ([date compare:now] == NSOrderedSame ||[date compare:now] == NSOrderedDescending) {
        _calendarPickerVC.selectedDate = date;
        selectedValue = http://www.mamicode.com/[DATE_FORMATER stringFromDate:_calendarPickerVC.selectedDate];>

特别记得不要忘记设置代理： _calendarPickerVC.calendar.delegate =self;

完！