我有一个UICollectionView
let cellIdentifier = "DayCollectionViewCell"
class ViewController: UIViewController, UICollectionViewDataSource,UICollectionViewDelegate {
@IBOutlet weak var button: UIButton!
var dates = [Date?]()
var startDate: Date?
@IBOutlet weak var daysCollectionView: UICollectionView!
override func viewDidLoad() {
super.viewDidLoad()
daysCollectionView.register(UINib.init(nibName: "DayCollectionViewCell", bundle: nil), forCellWithReuseIdentifier: cellIdentifier)
let allDates = Helper.generateRandomDate(daysBack: 900, numberOf: 3)
self.dates = allDates.sorted(by: {
$0!.compare($1!) == .orderedAscending
})
print(self.dates)
startDate = self.dates.first! ?? Date()
daysCollectionView.delegate = self
daysCollectionView.dataSource = self
// Do any additional setup after loading the view, typically from a nib.
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 900
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = daysCollectionView.dequeueReusableCell(withReuseIdentifier: cellIdentifier, for: indexPath) as! DayCollectionViewCell //ON THIS LINE!!!!! Thread 1: EXC_BAD_ACCESS (code=1, address=0x5b9c38eb4f78)
let cellDate = Calendar.current.date(byAdding: .day, value: indexPath.item, to: self.startDate!)
if self.dates.contains(where: { Calendar.current.isDate(cellDate!, inSameDayAs: $0!) }) {
print("same")
cell.backgroundColor = UIColor.red
} else {
print("not me")
cell.backgroundColor = UIColor.lightGray
}
return cell
}
}
在另一个文件里
class DayCollectionViewCell: UICollectionViewCell {
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}
func clearArrow(){
self.layer.sublayers = nil
}
func drawArrow(){
let start_x = self.bounds.minX
let start_y = self.bounds.minY
let top_width = self.bounds.width
let tick_height = self.bounds.height
let tip_height = CGFloat(10)
let tip_flare = CGFloat(6)
let arrowLayer = CAShapeLayer()
let path = UIBezierPath()
path.move(to: CGPoint(x: start_x, y: start_y + tick_height))
path.addLine(to: CGPoint(x: start_x + top_width,y: start_y + tick_height))
path.addLine(to: CGPoint(x: start_x + top_width + tip_flare,y: start_y+tick_height+tip_height))
path.addLine(to: CGPoint(x: start_x - tip_flare,y: start_y + tick_height + tip_height))
path.close()
arrowLayer.path = path.cgPath
arrowLayer.fillColor = UIColor(red:0.99, green:0.13, blue:0.25, alpha:1.0).cgColor
self.layer.addSublayer(arrowLayer)
}
override var isSelected: Bool{
didSet{
if self.isSelected
{
self.drawArrow()
}
else
{
self.clearArrow()
}
}
}
}
然后是DayCollectionViewCell.xib 文件:
