Swift无法识别的选择器发送到实例错误

Question

我最近将我的项目从 Objective-C 转换为 Swift，这样做时，每当我单击表格视图单元格中的按钮时，都会出现此错误。我有多个单元格填充了来自 mysql 服务器的信息。我有两个按钮，一个跟随按钮和一个跟随按钮，当单击一个时，另一个应该显示。我已经为此工作了一段时间，但一直被这个错误困扰。

单击表格视图中的按钮时出现错误

CustomCellSwift[1425:372289] -[CustomCellSwift.ViewController followButtonClick:]: unrecognized selector sent to instance 0x100b13a40

在 CustomCell.swift 中

class CustomCell: UITableViewCell {

@IBOutlet weak var firstStatusLabel: UILabel!
@IBOutlet weak var secondStatusLabel: UILabel!
@IBOutlet weak var myImageView: UIImageView!
@IBOutlet weak var followButton: UIButton!
@IBOutlet weak var followedButton: UIButton!

override func awakeFromNib() {
    super.awakeFromNib()

    self.followButton.isHidden = true
    self.followedButton.isHidden = true
}

override func setSelected(_ selected: Bool, animated: Bool) {
    super.setSelected(selected, animated: animated)
}

func populateCell(_ testObject: Test, isFollowed: Bool, indexPath: IndexPath, parentView: Any) {

    // Loading Background Color
    self.backgroundColor = UIColor.white

    // Loading Status Labels
    self.firstStatusLabel.text = testObject.testStatus1
    self.secondStatusLabel.text = testObject.testStatus2
    self.firstStatusLabel.isHidden = true
    self.secondStatusLabel.isHidden = true

    if isFollowed {
        self.followedButton.tag = indexPath.row
        self.followedButton.addTarget(parentView, action: Selector(("followedButtonClick")), for: .touchUpInside)
        self.followedButton.isHidden = false
        self.followButton.isHidden = true

        // Status Labels
        self.firstStatusLabel.isHidden = false
        self.secondStatusLabel.isHidden = false

    }
    else {
        self.followButton.tag = indexPath.row
        self.followButton.addTarget(parentView, action: Selector(("followButtonClick:")), for: .touchUpInside)
        self.followedButton.isHidden = true
        self.followButton.isHidden = false

        // Status Labels
        self.firstStatusLabel.isHidden = false // True when done testing
        self.secondStatusLabel.isHidden = false // True when done testing

    }
  }
}

ViewController.swift

CellForRowAt 索引路径

public func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

    let CellIdentifier = "Cell"
    var cell = tableView.dequeueReusableCell(withIdentifier: CellIdentifier) as! CustomCell

    if cell != cell {
        cell = CustomCell(style: UITableViewCellStyle.default, reuseIdentifier: CellIdentifier)
    }

    // Coloring TableView
    myTableView.backgroundColor = UIColor.white

    // Configuring the cell
    var testObject: Test

    if !isFiltered {
        if indexPath.section == 0 {
            testObject = followedArray[indexPath.row] 
            cell.populateCell(testObject, isFollowed: true, indexPath: indexPath, parentView: self)
        }
        else if indexPath.section == 1 {
            testObject = testArray[indexPath.row] 
            cell.populateCell(testObject, isFollowed: false, indexPath: indexPath, parentView: self)
        }
    }
    else {
        testObject = filteredArray[indexPath.row] as! Test
        cell.populateCell(testObject, isFollowed: false, indexPath: indexPath, parentView: self)
    }

    return cell
}

关注按钮代码

@IBAction func followButtonClick(sender: UIButton!) {

    // Adding row to tag
    let buttonPosition = (sender as AnyObject).convert(CGPoint.zero, to: self.myTableView)
    if let indexPath = self.myTableView.indexPathForRow(at: buttonPosition) {

        // Showing Status Labels
        let cell = self.myTableView.cellForRow(at: indexPath) as! CustomCell
        cell.firstStatusLabel.isHidden = false
        cell.secondStatusLabel.isHidden = false

        // Change Follow to Following
        (sender as UIButton).setImage(UIImage(named: "follow.png")!, for: .normal)
        cell.followButton.isHidden = true
        cell.followedButton.isHidden = false
        self.myTableView.beginUpdates()

        // ----- Inserting Cell to Section 0 -----
        followedArray.insert(testArray[indexPath.row], at: 0)
        myTableView.insertRows(at: [IndexPath(row: 0, section: 0)], with: .fade)

        // ----- Removing Cell from Section 1 -----
        testArray.remove(at: indexPath.row)
        let rowToRemove = indexPath.row
        self.myTableView.deleteRows(at: [IndexPath(row: rowToRemove, section: 1)], with: .fade)

        self.myTableView.endUpdates()

    }
}

取消关注按钮代码与关注按钮相同。

我认为问题出在按钮 selector(("")) 中的 CustomCell.swift 中，但错误是 -[CustomCellSwift.ViewController followButtonClick:]，这意味着在 ViewController 中的后续按钮代码中，但我不知道该怎么办了。

Answer 1

Swift 3 的两个变化：

选择器应如下所示：

#selector(ClassName.followButtonClick(_:))

函数应该有一个下划线：

@IBAction func followButtonClick(_ sender: UIButton!) { ...

注意这两个应该在同一个类中，否则，请确保初始化ClassName 类。

如果您希望选择器方法（followButtonClick(_:)）位于UITableViewCell 类中。删除@IBAction（我认为你不需要它）：

func followButtonClick(_ sender: UIButton!) { ... 

Answer 2

对于Swift3，您需要更改以下内容：

self.followedButton.addTarget(parentView, action: Selector(("followedButtonClick")), for: .touchUpInside)

与：

self.followedButton.addTarget(parentView, action: #selector(self.followButtonClick(_:)), forControlEvents: .touchUpInside)

Answer 3

对于Swift 2.2 和Xcode 8：

self.followedButton.addTarget(parentView, action: #selector(CustomCell.followButtonClick(_:)), forControlEvents: .TouchUpInside)