Question

我有UICollectionViewCell，UIButton。我有两种不同的行为。第一个，当用户按下单元格时，它将转到didSelectITemAt的另一个视图;第二个，当用户按下单元格内的UIButton时我的问题是，在MyCollectionViewCell的Swift代码中，当我编写代码时，我无法执行segue：

self.performSegue(withIdentifier: "toStoreFromMyDiscounts", sender: nil)

它说错误：

MyCollectionViewCell类型的值没有成员performSegue。

我也写不出prepareForSegue，它不会自动完成。

如何从单元格创建segue，这与单击单元格本身不同？

Answer 1

您无法从performSegue子类中致电UICollectionViewCell，因为UICollectionViewCell上的no interface declared就是这样。

它工作didSelectItemAtIndexPath()的原因是因为我认为UICollectionView的{{3}}是UIViewController子类，具有名为delegate的函数

您需要在UIViewController中点击按钮时通知您的UICollectionViewCell，以获得各种可能性，例如KVO或使用代表。

这是一个小代码片段，如何使用KVO。这个解决方案很棒，只要你不在乎，按下按钮的是哪个单元格。

import UIKit

class CollectionViewCell: UICollectionViewCell {
    @IBOutlet weak var button: UIButton!
}

class CollectionViewController: UIViewController {
    @IBOutlet weak var collectionView: UICollectionView!
}

extension CollectionViewController: UICollectionViewDataSource {

    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 1
    }

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) ->  UICollectionViewCell {
        let cell: CollectionViewCell = self.collectionView.dequeueReusableCell(withReuseIdentifier: "Cell", for: indexPath) as! CollectionViewCell
        // Add your `UIViewController` subclass, `CollectionViewController`, as the target of the button
        // Check out the documentation of addTarget(:) https://developer.apple.com/reference/uikit/uicontrol/1618259-addtarget
        cell.button.addTarget(self, action: #selector(buttonTappedInCollectionViewCell), for: .touchUpInside)
        return cell
    }

    func buttonTappedInCollectionViewCell(sender: UIButton) {
        self.performSegue(withIdentifier: "toStoreFromMyDiscounts", sender: nil)
    }
}

修改如果您关心触摸事件发生在哪个单元格中，请使用委托模式。

import UIKit protocol CollectionViewCellDelegate: class { // Declare a delegate function holding a reference to `UICollectionViewCell` instance func collectionViewCell(_ cell: UICollectionViewCell, buttonTapped: UIButton) } class CollectionViewCell: UICollectionViewCell { @IBOutlet weak var button: UIButton! // Add a delegate property to your UICollectionViewCell subclass weak var delegate: CollectionViewCellDelegate? @IBAction func buttonTapped(sender: UIButton) { // Add the resposibility of detecting the button touch to the cell, and call the delegate when it is tapped adding `self` as the `UICollectionViewCell` self.delegate?.collectionViewCell(self, buttonTapped: button) } } class CollectionViewController: UIViewController { @IBOutlet weak var collectionView: UICollectionView! } extension CollectionViewController: UICollectionViewDataSource { func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int { return 1 } func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell { let cell: CollectionViewCell = self.collectionView.dequeueReusableCell(withReuseIdentifier: "Cell", for: indexPath) as! CollectionViewCell // Asssign the delegate to the viewController cell.delegate = self return cell } } // Make `CollectionViewController` confrom to the delegate extension CollectionViewController: CollectionViewCellDelegate { func collectionViewCell(_ cell: UICollectionViewCell, buttonTapped: UIButton) { // You have the cell where the touch event happend, you can get the indexPath like the below let indexPath = self.collectionView.indexPath(for: cell) // Call `performSegue` self.performSegue(withIdentifier: "toStoreFromMyDiscounts", sender: nil) } }

Answer 2

另一种解决方案也像魅力一样：

extension YOURViewController : UICollectionViewDataSource
{
    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell
    {
         let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "YOURCell", for: indexPath) as! YOURCollectionViewCell

         cell.butTapped = {
             [weak self] (YOURCollectionViewCell) -> Void in
             // do your actions when button tapped
         }
    }        
    return cell
}


class YOURCollectionViewCell: UICollectionViewCell
{
     var butQRTapped: ((YOURCollectionViewCell) -> Void)?
     @IBAction func deleteButtonTapped(_ sender: AnyObject) {
         butTapped?(self)
     }
}

Answer 3

这是一个优雅的解决方案，只需要几行代码：

创建自定义UICollectionViewCell子类
使用情节提要，为按钮的“ Touch Up Inside ”事件定义IBAction
定义闭包
从IBAction调用闭包

快速4 + 代码

class MyCustomCell: UICollectionViewCell {

        static let reuseIdentifier = "MyCustomCell"

        @IBAction func onAddToCartPressed(_ sender: Any) {
            addButtonTapAction?()
        }

        var addButtonTapAction : (()->())?
    }

下一步，在

的闭包内部实现要执行的逻辑

override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        guard let cell = collectionView.dequeueReusableCell(withReuseIdentifier: MyCustomCell.reuseIdentifier, for: indexPath) as? MyCustomCell else {
            fatalError("Unexpected Index Path")
        }

        // Configure the cell
        // ...


        cell.addButtonTapAction = {
            // implement your logic here, e.g. call preformSegue()  
            self.performSegue(withIdentifier: "your segue", sender: self)              
        }

        return cell
    }

您也可以将这种方法用于表视图控制器。

从UICollectionViewCell按钮执行Segue，与Cell Click不同

3 个答案: