将 UILongPressGesture 添加到单元格而不是 CollectionView

Question

我正在尝试将UILongGestureRecognizer添加到我的自定义 CollectionView 单元中，但处理程序 function从未调用过。 这是来自自定义单元格的gesture和handlerFunc ：

let longPress = UILongPressGestureRecognizer(target: self, action: #selector(handleLongPress(_:)))

@objc func handleLongPress(_ recognizer: UILongPressGestureRecognizer) {
    switch recognizer.state {
    case .possible:
        break
    case .began:
        print("began")
        break
    case .changed:
        break
    case .ended:
        print("ended")
        break
    case .cancelled:
        break
    case .failed:
        break
    @unknown default:
        break
    }
}

另外，这是我的cell configure function：

func configure(with viewModel: RecordsCollectionViewCellViewModel, itemCount: Int) {
    longPress.numberOfTapsRequired = 1
    longPress.minimumPressDuration = 0.3
    longPress.delaysTouchesBegan = true
    longPress.delegate = self
    
    self.bringSubviewToFront(gestureView)
    gestureView.isUserInteractionEnabled = true
    gestureView.addGestureRecognizer(longPress)

}

gestureView视图是单元格顶部的透明视图。

Answer 1

我过去尝试过这个并且遇到了问题，我相信与实际 collectionView 上的 contextMenu 交互有关。

您可以通过将手势处理程序放在 collectionView 本身上并获取手势位置来修复它，然后按照此链接将单元格放在位置；

如何制作表格viewcell-handle-tap-and-longpress

Answer 2

如果您正在寻找最佳解决方案，我认为有更好的解决方案，例如将UILongPressGestureRecognizer添加到集合视图并确定点击了哪个单元格，或者您是否需要在长按func collectionView(_ collectionView: UICollectionView, contextMenuConfigurationForItemAt indexPath和推荐它们的原因是因为集合视图上已经有一些手势管理。

但是，如果您已经考虑了所有这些并且仍然觉得您的解决方案适合您，我认为问题在于这一行let longPress = UILongPressGestureRecognizer(target: self, action: #selector(handleLongPress(_:)))默认情况下，这似乎与单元格一起初始化。

我觉得也许当单元被重用时，在func configure中没有正确配置某些东西

我会做这些改变：

func configure(with viewModel: RecordsCollectionViewCellViewModel, itemCount: Int) {

        // Remove any previous gesture recognizers, maybe this is not needed 
        gestureView.gestureRecognizers?.removeAll()

        // Initialize a new gesture recognizer
        let longPress = UILongPressGestureRecognizer(target: self,
                                                     action: #selector(handleLongPress))
        
        // longPress.numberOfTapsRequired = 1 - not needed
        
        longPress.minimumPressDuration = 0.3
        
        // longPress.delaysTouchesBegan = true - not needed
        
        // longPress.delegate = self - not needed unless you are doing something else
        
        gestureView.isUserInteractionEnabled = true
        
        gestureView.addGestureRecognizer(longPress)
}

试试看，现在是否正在调用 function handleLongPress ？ 就我而言，这是可行的。

Answer 3

仅在 viewDidLoad() 中调用 setLongPress()

func setLongPress(){
     let lpgr = UILongPressGestureRecognizer(target: self, action: #selector(handleLongPress(_:)))
     lpgr.minimumPressDuration = 0.5
     lpgr.delaysTouchesBegan = true
     lpgr.delegate = self
     self.CollectionView.addGestureRecognizer(lpgr)
}

@objc func handleLongPress(_ gestureRecognizer: UILongPressGestureRecognizer?) {
    if gestureRecognizer?.state != .ended {
        return
    }
    let p = gestureRecognizer?.location(in: projectCollectionView)

    let indexPath = CollectionView.indexPathForItem(at: p ?? CGPoint.zero)
    if indexPath == nil {
        print("couldn't find index path")
    } else {
        // get the cell at indexPath (the one you long pressed)
        var cell: UICollectionViewCell? = nil
        if let indexPath = indexPath {
            // your action here
        }
        // do stuff with the cell
    }
}