如何从目标函数集（Swift 3）访问 UICollectionView 中的按钮

Question

在我的视图控制器中，我有一个集合视图，它在渲染时显示 3 个单元格，每个单元格都有一个标签和一个按钮。标签显示颜色的名称，按钮具有显示色样的背景图像。

我希望这样，每当您单击其中一个按钮时，该按钮周围会出现深色边框，而其他按钮上会出现浅色边框，以指示单击的按钮被“选中”。或者，我可以通过根据图像的选定状态更改图像来做到这一点 - 但我的问题仍然是一样的。

如何访问其他两个按钮以切换它们的属性？

我实现了一个脚本，允许我为某人单击的按钮添加边框 - 但我无法弄清楚如何访问 CollectionView 的其他单元格中的其他按钮以更改其边框属性。

这是我的源代码（去掉了不相关/不相关的位）

class trimSelectorVC: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource {

    @IBOutlet weak var trimSelector: UICollectionView!

    struct trimObject {
        var trimName: String
        var trimButton: String
        var trimID: Int
    }

    var trimArray: [trimObject] = []

    override func viewDidLoad() {
        super.viewDidLoad()
        trimArray.append(trimObject(trimName: "Chrome", trimButton: "chrome-swatch", trimID: 0))
        trimArray.append(trimObject(trimName: "Gold", trimButton: "gold-swatch", trimID: 1))
        trimArray.append(trimObject(trimName: "Gun Metal", trimButton: "gunmetal-swatch", trimID: 2))

        trimSelector.delegate = self
        trimSelector.dataSource = self
    }


    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
    }

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

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

        //Set the label text
        cell.trimLabel.text = trimArray[indexPath.item].trimName

        //Set the image for the button
        cell.trimButton.setImage(UIImage(named: trimArray[indexPath.item].trimButton), for: UIControlState.normal)

        //Sets a target function for the button
        cell.trimButton.addTarget(self, action: #selector(selectedSwatch), for: .touchUpInside)

        return cell
    }


    func selectedSwatch(sender: UIButton) {

        //These set the "selected" border to the button you clicked on.
        sender.layer.borderWidth = 2
        sender.layer.borderColor = UIColor(red: 83/255, green: 71/255, blue: 65/255, alpha: 1.00).cgColor


    }
}

谁能告诉我如何访问我的“selectedSwatch”功能中的其他按钮？

Answer 1

您可以通过多种方式处理此问题。 UICollectionView 视图有一个 visibleCells() 方法，它返回其可见单元格的数组。您可以使用它来获取指向单元格的指针。您需要一种方法来确定哪个是哪个。例如，您可以使用indexPath(for: UICollectionViewCell) 找出每个单元格的索引路径。

Answer 2

我不知道这是否有帮助，但是如果将 IndexPath 存储在 cellForItemAt 方法的结构中呢？

你将拥有：

struct trimObject {
    var trimName: String
    var trimButton: String
    var trimID: Int
    var idx : IndexPath
}

然后：

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {

let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as! trimSelectionCell
            ....

 trimArray[indexPath.item].idx = indexPath
     .... 
}

在您的 selectedSwatch 方法中：

func selectedSwatch(sender: UIButton) {

    //These set the "selected" border to the button you clicked on.
    sender.layer.borderWidth = 2
    sender.layer.borderColor = UIColor(red: 83/255, green: 71/255, blue: 65/255, alpha: 1.00).cgColor

    if let cell = (sender.superview as? UICollectionViewCell) {

        //Cell with the button selected:
        let idx = collectionView.indexPath(for: cell)

        //array of the other objects:
        let allOtherObjects = trimArray.filter { ($0 as! trimObject).idx != idx }

        allOtherObject.forEach({ (trimObj) in
            let cell = collection.cellForItem(at: trimObj.idx)
            //Do whatever yo need to do...
            //cell.trimButton.layer
        })
    }

}

Answer 3

可能为时已晚，但对某些人仍然有用 斯威夫特 4 版本： 您可以将发件人超级视图用作 UiCollectionViewCell * 在集合视图单元格中考虑发送者的层次结构

func selectedSwatch(sender: UIButton) {
   let cell = sender.superview?.superview as! trimSelectionCell
   //cell.yourbtn 
}

Answer 4

试试这个，

 class trimSelectorVC: UIViewController, UICollectionViewDelegate, 
 UICollectionViewDataSource {

@IBOutlet weak var trimSelector: UICollectionView!

struct trimObject {
    var trimName: String
    var trimButton: String
    var trimID: Int
    var isSelected : String
}

var trimArray: [trimObject] = []

override func viewDidLoad() {
    super.viewDidLoad()
    trimArray.append(trimObject(trimName: "Chrome", trimButton: "chrome-swatch", trimID: 0,isSelected : "0"))
    trimArray.append(trimObject(trimName: "Gold", trimButton: "gold-swatch", trimID: 1,isSelected : "0"))
    trimArray.append(trimObject(trimName: "Gun Metal", trimButton: "gunmetal-swatch", trimID: 2,isSelected : "0"))

    trimSelector.delegate = self
    trimSelector.dataSource = self
}


override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
}

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

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

    //Set the label text
    cell.trimLabel.text = trimArray[indexPath.item].trimName

    //Set the image for the button
    cell.trimButton.setImage(UIImage(named: 
  trimArray[indexPath.item].trimButton), for: UIControlState.normal)
   if(trimArray[indexPath.item].isSelected == "0"){
   // button not clicked
  // change shadow color of button

    }
   else
    {
   // button  clicked
       cell.trimButton.layer.borderWidth = 2
      cell.trimButton.layer.borderColor = UIColor(red: 83/255, green: 
       71/255,blue: 65/255, alpha: 1.00).cgColor
    }
     // set tag to the button
     cell.trimButton.tag = indexPath.item 

    //Sets a target function for the button
    cell.trimButton.addTarget(self, action:#selector(selectedSwatch), 
         for: .touchUpInside)

     return cell
  }


func selectedSwatch(sender: UIButton) {

    //These set the "selected" border to the button you clicked on.

  let index = sender.tag
   for obj in trimArray {
   obj.isSelected = "0"
   }

   trimArray[index].isSelected = "1"

  collectionView.reloadData()
}

}