代码之家 › 专栏 › 技术社区 › Extragorey

从UICollectionViewCell传播自定义事件

uicollectionview swift ios

Extragorey · 技术社区 · 8 年前

伪代码:

class MyCell : UICollectionViewCell {
    @IBAction func myButton_touchUpInside(_ sender: UIButton) {
        // Do stuff, then propagate an event to the UICollectionView
        Event.fire("cellUpdated")
    }
}

class MyViewController : UIViewController {
    @IBAction func collectionView_cellUpdated(_ sender: UICollectionView) {
        // Update stuff in the view controller 
        // to reflect changes made in the collection view
    }
}

理想情况下,我定义的事件将出现在界面生成器中的默认操作出口旁边,允许我将其拖动到视图控制器代码中以创建上述内容 collectionView_cellUpdated @IBInspectable 用于公开自定义属性。

有没有办法在本机Swift 3中实现这样的模式?或者,如果没有,有什么图书馆可以做到这一点?

2 回复 | 直到 8 年前

PGDev 8 年前

我不完全理解你的问题,但从我得到的情况来看,你可以简单地使用 closure UIButton 将事件点击回 UIViewController .

1、自定义 UICollectionViewCell

class MyCell: UICollectionViewCell
{
    var tapHandler: (()->())?

    @IBAction func myButton_touchUpInside(_ sender: UIButton)
    {
        tapHandler?()
    }
}

2. MyViewController

class MyViewController: UIViewController, UICollectionViewDataSource
{
    //YOUR CODE..

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell
    {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as! MyCell
        cell.tapHandler = {
            //Here you can do your custom handling
        }
        return cell
    }
}

如果你面临任何问题,请告诉我。

jlmurph 8 年前

最好的做法是为您的自定义单元类创建一个自定义协议

protocol CustomCellProtocolDelegate {
   func custom(cell: YourCellClass, hadButton: UIButton, pressedWithInfo : [String:Any]?)
}

class YourCellClass: UICollectionViewCell {

   var delegate : CustomCellProtocolDelegate?

   var indexPath : IndexPath? //Good practice here to have an indexPath parameter

   var yourButton = UIButton()

   init(frame: CGRect) {
      super.init(frame: frame)
      yourButton.addTarget(self, selector: #selector(triggerButton(sender:)))
   }
   func triggerButton(sender: UIButton) {
      if let d = self.delegate {
         d.custom(cell: self, hadButton: sender, pressedWithInfo : /*Add info if you want*/)
      }
   }

}

在控制器中,将其与委托相一致,并将委托应用于 cellForItem: atIndexPath :

class YourControllerThatHasTheCollectionView : UIViewController, CustomCellProtocolDelegate {

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "identifier", for: indexPath) as! YourCellClass
        cell.delegate = self
        cell.indexPath = indexPath
        return cell
    }

   func custom(cell: YourCellClass, hadButton: UIButton, pressedWithInfo : [String:Any]?) {

        //Here you can process which button was selected, etc.. and apply your changes to your collectionview

   }

}

最佳做法是在 pressedWithInfo indexPath

    protocol CustomCellProtocolDelegate {
       func custom(cell: YourCellClass, hadButton: UIButton, pressedAt: IndexPath, withInfo : [String:Any]?)
    }

    func triggerButton(sender: UIButton) {
       if let d = self.delegate {
           d.custom(cell: self, hadButton: sender, pressedAt: indexPath!, withInfo : /*Add info if you want*/)
       }
    }