Swift 3.0：自定义 CollectionView 标题按钮单击答案

【问题标题】：Swift 3.0 : Custom CollectionView header button clickSwift 3.0：自定义 CollectionView 标题按钮单击
【发布时间】：2017-11-28 09:06:26
【问题描述】：

我已经制作了一个自定义的 collectionview 单元格。我已经通过这段代码将它作为集合视图的标题：

func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
    if kind == UICollectionElementKindSectionHeader {

        let cell = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: "HeaderCell", for: indexPath) as! GridHeaderCollectionViewCell
        cell.pagePluginBtn.tag = 0
        cell.tag = 0
        cell.nameLabel.text = pageRecord["GroupName"] as? String
        cell.pagePluginBtn.addTarget(self, action: #selector(TappedOnPagePluginBtn(sender:)), for: .touchUpInside)
        return cell
    }
    abort()
}

func TappedOnPagePluginBtn(sender:UIButton){

    print("in plugin")
}

单元格定义为：

class GridHeaderCollectionViewCell: UICollectionViewCell {

@IBOutlet weak var nameLabel: UILabel!
@IBOutlet weak var pagePluginBtn: UIButton!
}

TappedOnPagePluginBtn() 根本没有被调用。有没有办法让collectionView的headerView中的按钮可以点击？

【问题讨论】：

标签： ios swift3 uibutton uicollectionview uicollectionviewcell

【解决方案1】：

像这样改变你的单元格：

public typealias ButtonAction = () -> Void

class GridHeaderCollectionViewCell: UICollectionViewCell {

    @IBOutlet weak var nameLabel: UILabel!
    @IBOutlet weak var pagePluginBtn: UIButton!

    var pagePluginButtonAction : ButtonAction?


    override func viewDidLoad(){
        pagePluginBtn.addTarget(self, action: #selector(pagePluginBtnClick(_:)), for: .touchUpInside)
    }

    @objc func pagePluginBtnClick(_ sender : UIButton){
        guard let pagePluginButtonAction = pagePluginButtonAction else{
            return
        }

        pagePluginButtonAction()
    }
}

你需要做的就是：

override func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {

    let view = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: headerReuseIdentifier, for: indexPath) as! GridHeaderCollectionViewCell

    view.pagePluginButtonAction = {
        self.TappedOnPagePluginBtn()
    }

    return view
}

func TappedOnPagePluginBtn(){

    print("in plugin")
}

【讨论】：

【解决方案2】：

第二种方法（不是第二种方法，是我的更好版本）来自 ALCameraViewController 的创建者 AlexLittlejohn。

您可以创建 UIButton 扩展来添加添加目标等操作。

typealias ButtonAction = () -> Void

extension UIButton {

    private struct AssociatedKeys {
        static var ActionKey = "ActionKey"
    }

    private class ActionWrapper {
        let action: ButtonAction
        init(action: @escaping ButtonAction) {
            self.action = action
        }
    }

    var action: ButtonAction? {
        set(newValue) {
            removeTarget(self, action: #selector(performAction), for: .touchUpInside)
            var wrapper: ActionWrapper? = nil
            if let newValue = newValue {
                wrapper = ActionWrapper(action: newValue)
                addTarget(self, action: #selector(performAction), for: .touchUpInside)
            }

            objc_setAssociatedObject(self, &AssociatedKeys.ActionKey, wrapper, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
        }
        get {
            guard let wrapper = objc_getAssociatedObject(self, &AssociatedKeys.ActionKey) as? ActionWrapper else {
                return nil
            }

            return wrapper.action
        }
    }

    @objc func performAction() {
        guard let action = action else {
            return
        }

        action()
    }
}

那么;

override func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {

    let view = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: headerReuseIdentifier, for: indexPath) as! GridHeaderCollectionViewCell

    view.pagePluginBtn.action = {
        print("yeah we catch it!")
    }

    return view
}

【讨论】：