選擇器獲取indexPath UICollectionView Swift 3.0

Question

我試圖在兩次點擊時在單元格上獲取indexPath 。 我像這樣在Selector傳遞參數，但它給出了錯誤。 正確的格式是什么？

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    if  let subOptioncell : SubOptionsCollectionViewCell = collectionView.dequeueReusableCell(withReuseIdentifier: subOptionsCVReuseIdentifier, for: indexPath) as! SubOptionsCollectionViewCell

          let imageNamed = "\(customizeOptionSelected[indexPath.row])"
          subOptioncell.subOptionsImage.image = UIImage(named: imageNamed)

          let tap =  UITapGestureRecognizer(target: self, action: #selector(doubleTapped(sender: indexPath)))
          tap.numberOfTapsRequired = 2
          collectionView.addGestureRecognizer(tap)   

          return subOptioncell
    }
}

func doubleTapped(sender: IndexPath) {
    print("Double Tap")
}

Answer 1

首先，您要將tapGesture添加到collectionView而不是subOptioncell 。

它應該是：

subOptioncell.addGestureRecognizer(tap)

代替：

collectionView.addGestureRecognizer(tap)

您不能使用UIGestureRecognizer selector傳遞其他實例，唯一可以傳遞的實例是UI(Tap)GestureRecognizer 。 如果您想要該單元格的indexPath，可以嘗試這樣。 首先，像這樣設置TapGesture的selector 。

let tap =  UITapGestureRecognizer(target: self, action: #selector(doubleTapped(sender:)))

現在方法應該是這樣的：

func doubleTapped(sender: UITapGestureRecognizer) {
    if let cell = sender.view as? SubOptionsCollectionViewCell, let indexPath = self.collectionView.indexPath(for: cell) {
         print(indexPath)
    }       
}

編輯：如果要在單元格上雙擊顯示/隱藏圖像，則需要使用indexPath處理該indexPath ，為此首先聲明一個IndexPath實例，然后在cellForItemAt indexPath使用它。

var selectedIndexPaths = IndexPath()

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    //Your code 
    //Now add below code to handle show/hide image
    cell.subOptionSelected.isHidden = self.selectedIndexPaths != indexPath
    return cell
}

現在doubleTapped的行動UITapGestureRecognizer設置selectedIndexPath 。

func doubleTapped(sender: UITapGestureRecognizer) {
    if let cell = sender.view as? SubOptionsCollectionViewCell, let indexPath = self.collectionView.indexPath(for: cell) {
         if self.selectedIndexPaths == indexPath {
             cell.subOptionSelected.isHidden = true
             self.selectedIndexPaths = IndexPath()
         }
         else {
             cell.subOptionSelected.isHidden = false
             self.selectedIndexPaths = indexPath
         }           
    }       
}

Answer 2

您所用的正確選擇器是doubleTapped: 那是

let tap =  UITapGestureRecognizer(target: self, action: #selector(doubleTapped:))

調用目標方法時，不能激發任意參數。 您可以通過以下方式在subOptioncell上設置目標

let tap =  UITapGestureRecognizer(target: subOptioncell, action: #selector(doubleTapped:))

您可以在subOptioncell設置所需的任意任意subOptioncell

Answer 3

您需要以這種方式添加選擇器

let tap = UITapGestureRecognizer(target: self, action: #selector(YourViewControllerName.doubleTapped(_:)))
subOptioncell.addGestureRecognizer(tap)

Answer 4

將您的代碼更改為。

let tap =  UITapGestureRecognizer(target: self, action: #selector(doubleTapped(_:)))

和功能。

func doubleTapped(_ sender: AnyObject) {
    print("Double Tap")
}

Answer 5

在您的數據源方法

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
      if let subOptioncell : SubOptionsCollectionViewCell = collectionView.dequeueReusableCell(withReuseIdentifier: subOptionsCVReuseIdentifier, for: indexPath) as! SubOptionsCollectionViewCell{
         //... your code
         subOptioncell.addGestureRecognizer(tap)
         return subOptioncell
       }

}

然后在函數cellTapped()

func cellTapped(sender: UITapGestureRecognizer){

    let tapLocation = sender.location(in: yourCollectionView)
    let indexPath : IndexPath = yourCollectionView.indexPathForItem(at: tapLocation)!

    var currentIndex = 0

    if let cell = yourCollectionView.cellForItem(at: indexPath){
        currentIndex = cell.tag
    }

    print("Your Selected Index : \(currentIndex)")
}

快樂編碼！