iOS 自定义日历的实现
Swift 3.0版本的日历～～
1.首先，自定义日历的载体一定是CollectionView了～
2.然后，最关键的就是获取日历的信息了：当前日期，月份，1号是星期几，当前月份有多少天了... 通过这些信息，就可以确定每一个cell应该显示什么信息了.
//MARK: - Private
internal func dateInfo(date: Date) -> (DateComponents) {
let components = Calendar.current.dateComponents([Calendar.Component.year, Calendar.Component.month, Calendar.Component.day], from: date)
return components
}
internal func firstWeekDayThisMonth(date: Date) -> (Int) {
var components = Calendar.current.dateComponents([Calendar.Component.year, Calendar.Component.month, Calendar.Component.day], from: date)
components.day = 1
let firstDayOfMonthDate = Calendar.current.date(from: components)
let firstWeekDay = Calendar.current.ordinality(of: Calendar.Component.weekday, in: Calendar.Component.weekOfMonth, for: firstDayOfMonthDate!)
return firstWeekDay!
}
internal func totalDaysThisMonth(date: Date) -> (Int) {
let totalDaysThisMonth:Range = Calendar.current.range(of: Calendar.Component.day, in: Calendar.Component.month, for: date)!
return totalDaysThisMonth.count
}
3. 结构层次间下图～绿色的cell是负责显示日期的cell，黄色的cell是显示星期几的cell.
4.实现数据源方法. 如果需要实现其他功能，可以通过设置代理来实现.
extension CalendarViewController: UICollectionViewDataSource {
func numberOfSections(in collectionView: UICollectionView) -> Int {
return 2
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return section == 0 ? 7 : 37
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let currentDateComponents = dateInfo(date: Date())
var selectedComponents = dateInfo(date: date)
selectedComponents.day = indexPath.item - firstWeekDayThisMonth(date: date) + 2
if indexPath.section == 0 {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "DayOfAWeekCell", for: indexPath) as! CalendarDateCell
cell.dateLabel.text = dateArray[indexPath.item]
return cell
} else {
let cell = collectionView .dequeueReusableCell(withReuseIdentifier:"CalendarCell", for: indexPath) as! CalendarDateCell
if indexPath.item < firstWeekDayThisMonth(date: date) - 1 {
cell.dateLabel.text = " "
cell.backgroundColor = UIColor.clear
}else if indexPath.item >= firstWeekDayThisMonth(date: date) - 1 && (indexPath.item - firstWeekDayThisMonth(date: date) + 2) <= totalDaysThisMonth(date: date) {
cell.dateLabel.text = "\(indexPath.item - firstWeekDayThisMonth(date: date) + 2)"
if currentDateComponents == selectedComponents {
cell.backgroundColor = UIColor.orange
}else{
cell.backgroundColor = UIColor.green
}
}else {
cell.backgroundColor = UIColor.clear
cell.dateLabel.text = " "
}
return cell
}
}
}
extension CalendarViewController: UICollectionViewDelegate {
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
if indexPath.item >= firstWeekDayThisMonth(date: date) - 1 && (indexPath.item - firstWeekDayThisMonth(date: date) + 2) <= totalDaysThisMonth(date: date) {
var selectedComponents = dateInfo(date: date)
selectedComponents.day = indexPath.item - firstWeekDayThisMonth(date: date) + 2
self.selectedComponents = selectedComponents
self.selectedIndexPath = indexPath
}
}
}
设置好这些，大体的日历就可以实现了～
大体的思路就是这样，由于时间原因没有写的特别详细，有问题的小伙伴可以评论留言，我们可以一起讨论讨论.
或者直接去看源码～ 有什么意见欢迎大家指点～～
源码地址:https://github.com/LoKiLyn/Calendar