Swift：工具栏按钮没有反应

Question

下面的屏幕有两个按钮的工具栏。他们有处理程序。处理程序不会从按钮触发。我尝试将处理程序分配给红色按钮，它可以工作。我需要帮助才能找到错误

以下是我的代码：

let toolbar: UIToolbar = {
    let tb = UIToolbar(frame: CGRect(x: 0, y: 0, width: 10, height: 10))
    tb.isUserInteractionEnabled = true
    let doneButton = UIBarButtonItem(barButtonSystemItem: .done, target: self, action: #selector(choosen))
    let cancelButton = UIBarButtonItem(barButtonSystemItem: .cancel, target: self, action: #selector(cancelSelection))
    tb.items = [doneButton, cancelButton]
    tb.translatesAutoresizingMaskIntoConstraints = false
    return tb
}()

override func viewDidLoad() {
    super.viewDidLoad()

    let but = UIButton(frame: CGRect(x: 100, y: 100, width: 100, height: 100))
    but.addTarget(self, action: #selector(cancelSelection), for: .touchUpInside)
    but.backgroundColor = .red
    self.view.addSubview(but)
    self.view.obscure()

    weightPicker.addSubview(toolbar)

    toolbar.leadingAnchor.constraint(equalTo: weightPicker.leadingAnchor).isActive = true
    toolbar.trailingAnchor.constraint(equalTo: weightPicker.trailingAnchor).isActive = true
    toolbar.heightAnchor.constraint(equalToConstant: 50).isActive = true
    toolbar.topAnchor.constraint(equalTo: weightPicker.topAnchor).isActive = true

    self.view.addSubview(weightPicker)
    weightPicker.delegate = self
    weightPicker.leadingAnchor.constraint(equalTo: self.view.leadingAnchor).isActive = true
    weightPicker.trailingAnchor.constraint(equalTo: self.view.trailingAnchor).isActive = true
    weightPicker.heightAnchor.constraint(equalTo: self.view.heightAnchor, multiplier: 0.5).isActive = true
    weightPicker.bottomAnchor.constraint(equalTo: self.view.bottomAnchor).isActive = true
}

    @objc func choosen() {

    print(123)
    self.dismiss(animated: true, completion: nil)

}

@objc func cancelSelection() {

    print(123)
    self.dismiss(animated: true, completion: nil)

}

Answer 1

您好，在操作中尝试在功能名#selector('here'.cancelSelection)之前添加控制器类的名称或执行此操作#selector(self.cancelSelection)

Answer 2

尝试使用懒惰我认为问题是因为你使用自我

lazy var toolbar: UIToolbar = {
let tb = UIToolbar(frame: CGRect(x: 0, y: 0, width: 10, height: 10))
tb.isUserInteractionEnabled = true
let doneButton = UIBarButtonItem(barButtonSystemItem: .done, target: self, action: #selector(self.choosen))
let cancelButton = UIBarButtonItem(barButtonSystemItem: .cancel, target: self, action: #selector(self.cancelSelection))
tb.items = [doneButton, cancelButton]
tb.translatesAutoresizingMaskIntoConstraints = false
return tb}()

Answer 3

将UIToolbar添加到UIPickerView时似乎出错了。您可以改为添加一些容器视图：

override func viewDidLoad() {
    super.viewDidLoad()

    let containerView = UIView()
    containerView.translatesAutoresizingMaskIntoConstraints = false
    weightPicker.translatesAutoresizingMaskIntoConstraints = false

    view.addSubview(containerView)
    containerView.addSubview(toolbar)
    containerView.addSubview(weightPicker)

    NSLayoutConstraint.activate([
        containerView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
        containerView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
        containerView.bottomAnchor.constraint(equalTo: view.bottomAnchor),
        containerView.heightAnchor.constraint(equalTo: view.heightAnchor, multiplier: 0.5),
        toolbar.topAnchor.constraint(equalTo: containerView.topAnchor),
        toolbar.leadingAnchor.constraint(equalTo: containerView.leadingAnchor),
        toolbar.trailingAnchor.constraint(equalTo: containerView.trailingAnchor),
        toolbar.heightAnchor.constraint(equalToConstant: 50.0),
        weightPicker.topAnchor.constraint(equalTo: toolbar.bottomAnchor),
        weightPicker.leadingAnchor.constraint(equalTo: containerView.leadingAnchor),
        weightPicker.trailingAnchor.constraint(equalTo: containerView.trailingAnchor),
        weightPicker.bottomAnchor.constraint(equalTo: containerView.bottomAnchor)
    ])
}