错误：点击 UISegmentedControl 时将无法识别的选择器发送到实例

Question

点击其中一个片段触发操作时出现错误。

知道我做错了什么吗？

错误：

由于未捕获的异常“NSInvalidArgumentException”而终止应用程序，原因：'-[TestingSubclassing.MySegmentControl segmentActionWithSender:]：无法识别的选择器发送到实例 0x7f9217907750'

import UIKit

class MySegmentControl: UISegmentedControl {

    var actionName:Selector
    init(actionName: Selector) {
        self.actionName = actionName

        super.init(frame: .zero)

        insertSegment(withTitle: "Two", at: 0, animated: false)
        insertSegment(withTitle: "One", at: 1, animated: false)

        self.selectedSegmentIndex = 0

        self.layer.cornerRadius = 5.0
        self.backgroundColor = UIColor.red
        self.layer.borderWidth = 1
        self.layer.borderColor = UIColor.blue.cgColor

        self.addTarget(self, action: self.actionName, for: .valueChanged)

        self.translatesAutoresizingMaskIntoConstraints = false
    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

在 ViewController 中的使用

import UIKit

class ViewController: UIViewController {

    let segmentOne: MySegmentControl = {
        let segment1 = MySegmentControl(actionName:  #selector(segmentAction))
        return segment1
    }()

    override func viewDidLoad() {
        super.viewDidLoad()
        view.addSubview(segmentOne)
    }

    @objc func segmentAction(sender: UISegmentedControl) {
        print("segmentAction")
    }
}

我也尝试过如下更改选择器。

let segment1 = MySegmentControl(actionName: #selector(segmentAction(sender:))) 和 let segment1 = MySegmentControl(actionName: "segmentAction")

Answer 1

你一定是新手！ 你应该删除class MySegmentControl中的self.addTarget(self, action: self.actionName, for: .valueChanged)，添加下面的函数viewDidLoad()：

segmentOne.addTarget(self, action: #selector(segmentAction(sender:)), for: .valueChanged)