ios - 如何在 swift 中将值从可重用的 PickerView.xib 中传递出去

Question

我创建了一个可重复使用的 UIPickerView:

PickerView.swift:

class PickerView: UIView, UIPickerViewDelegate, UIPickerViewDataSource {

    @IBOutlet weak var pickerView: UIPickerView!

    var labels: [String] = [] {
        didSet {
            self.pickerView.reloadAllComponents()
        }
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        Bundle.main.loadNibNamed("PickerView", owner: self, options: nil)
        self.addSubview(pickerView)
    }

    func numberOfComponents(in pickerView: UIPickerView) -> Int {
        return 1
    }
    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
        return labels.count
    }
    func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
        return labels[row]
    }        
}

这段代码使我可以通过将 UIView 的类设置为 PickerView 来初始化 UIPickerView:

要将数据添加到 UIPickerView，我只需创建一个 outlet 并通过该 outlet 添加数据。所以，我的 ViewController.swift 文件看起来像这样:

ViewController.swift:

class ViewController: UIViewController {

    @IBOutlet weak var pickerView: PickerView!

    override func viewDidLoad() {
        super.viewDidLoad()
        self.pickerView.labels = ["Label1","Label2","Label3"]
    }
}

---

这是我的问题:如何将 didSelectRow 值从选择器中传递出来以在 ViewController.swift 中使用？

Answer 1

创建自定义协议(protocol)

protocol MyPickerDelegate: NSObjectProtocol {
    func didSelectSomething(some: String)
}

在 PickerView.swift 中创建实例，例如

weak var myDelegate: MyPickerDelegate?

然后在viewDidLoad

self.pickerView.myDelegate = self

然后让你的UIViewController符合协议(protocol)

extension ViewController: MyPickerDelegate {
    func didSelectSomething(some: String) {
       // self.doStuff()
    }
}

然后在 PickerView.swift 中调用 didSelectRow 并在其中

self.myDelegate?.didSelectSomething(some: "SomeValue")