addTarget 和 addGestureRecognizer 不起作用，没有崩溃/错误 [英] addTarget and addGestureRecognizer not working, no crash/error
问题描述
我有一个带有表格的覆盖层，我想在背景中添加一个点击手势识别器以关闭视图，并将目标添加到覆盖层中的一个按钮，它执行相同的操作.
I a have an overlay with a table in and I'd like to add a Tap gesture recogniser to the background to dismiss the view and also addTarget to a button within the overlay which does the same thing.
叠加层按预期显示正常，但是每当我点击黑色背景或取消按钮时，什么也没有发生.我在这里搜索了答案，但没有找到任何有效的答案.我的代码如下，后附一张overlay的截图:
The overlay displays fine as expected, however whenever I tap the black background or the cancel button, nothing happens. I've searched for an answer here but nothing found has worked. My code is as follows, followed by a screenshot of the overlay:
class importedFileView: NSObject {
let blackView = UIView()
let importedFileContainerView: UIView = {
let importedFileContainerView = UIView(frame: .zero)
importedFileContainerView.backgroundColor = .white
importedFileContainerView.layer.cornerRadius = 10
importedFileContainerView.layer.masksToBounds = true
return importedFileContainerView
}()
let headerLabel: UILabel = {
let headerLabel = UILabel()
headerLabel.translatesAutoresizingMaskIntoConstraints = false
headerLabel.font = UIFont(name: "HelveticaNeue-Thin" , size: 24)
headerLabel.text = "Attach file"
headerLabel.textColor = .darkGray
headerLabel.adjustsFontSizeToFitWidth = true
return headerLabel
}()
let fileTableView: UITableView = {
let fileTableView = UITableView()
return fileTableView
}()
let updateDetailsButton: UIButton = {
let updateDetailsButton = UIButton()
updateDetailsButton.translatesAutoresizingMaskIntoConstraints = false
updateDetailsButton.backgroundColor = UIColor(r:40, g:86, b:131)
updateDetailsButton.setTitleColor(UIColor.white, for: .normal)
updateDetailsButton.setTitle("Attach selected files", for: .normal)
updateDetailsButton.titleLabel!.font = UIFont(name: "HelveticaNeue-Light" , size: 18)
updateDetailsButton.layer.cornerRadius = 2
return updateDetailsButton
}()
let cancelButton: UIButton = {
let cancelButton = UIButton()
cancelButton.translatesAutoresizingMaskIntoConstraints = false
cancelButton.backgroundColor = UIColor.white
cancelButton.setTitleColor(UIColor(r:40, g:86, b:131), for: .normal)
cancelButton.setTitle("Cancel", for: .normal)
cancelButton.titleLabel!.font = UIFont(name: "HelveticaNeue-Light" , size: 18)
cancelButton.layer.cornerRadius = 2
return cancelButton
}()
let frameHeight: CGFloat = 450
func showFormView(){
if let window = UIApplication.shared.keyWindow {
blackView.backgroundColor = UIColor(white: 0, alpha: 0.5)
window.addSubview(blackView)
window.addSubview(importedFileContainerView)
importedFileContainerView.addSubview(headerLabel)
importedFileContainerView.addSubview(fileTableView)
importedFileContainerView.addSubview(updateDetailsButton)
importedFileContainerView.addSubview(cancelButton)
cancelButton.addTarget(self, action: #selector(handleDismiss), for: .touchUpInside)
blackView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(handleDismiss)))
layoutViews()
fileTableView.frame = CGRect(x: 30, y: window.frame.height, width: window.frame.width - 60, height: 230)
let frameY = (window.frame.height - frameHeight) / 2
importedFileContainerView.frame = CGRect(x: 20, y: window.frame.height, width: window.frame.width - 40, height: self.frameHeight)
blackView.frame = window.frame
blackView.alpha = 0
UIView.animate(withDuration: 0.5, delay: 0, usingSpringWithDamping: 1, initialSpringVelocity: 1, options: .curveEaseOut, animations: {
self.blackView.alpha = 1
self.importedFileContainerView.frame = CGRect(x: 20, y: frameY, width: window.frame.width - 40, height: self.frameHeight)
}, completion: nil
)
}
}
func layoutViews(){
let views = ["v0" : headerLabel, "v1": fileTableView, "v2": updateDetailsButton, "v3": cancelButton]
let leftSpace = NSLayoutConstraint.constraints(withVisualFormat: "H:|-20.0-[v0]-20.0-|", options: NSLayoutFormatOptions(), metrics: nil, views: views)
let leftSpace1 = NSLayoutConstraint.constraints(withVisualFormat: "H:|-20.0-[v1]-20.0-|", options: NSLayoutFormatOptions(), metrics: nil, views: views)
let leftSpace2 = NSLayoutConstraint.constraints(withVisualFormat: "H:|-20.0-[v2]-20.0-|", options: NSLayoutFormatOptions(), metrics: nil, views: views)
let leftSpace3 = NSLayoutConstraint.constraints(withVisualFormat: "H:|-20.0-[v3]-20.0-|", options: NSLayoutFormatOptions(), metrics: nil, views: views)
let topSpacing = NSLayoutConstraint.constraints(withVisualFormat: "V:|-20.0-[v0(40)]-20.0-[v1(230)]-20.0-[v2(50)]-10.0-[v3(50)]-10.0-|", options: NSLayoutFormatOptions(), metrics: nil, views: views)
importedFileContainerView.addConstraints(topSpacing)
importedFileContainerView.addConstraints(leftSpace)
importedFileContainerView.addConstraints(leftSpace1)
importedFileContainerView.addConstraints(leftSpace2)
importedFileContainerView.addConstraints(leftSpace3)
}
func handleDismiss() {
UIView.animate(withDuration: 0.5,
delay: 0.0,
options: .curveEaseInOut,
animations: {
self.blackView.alpha = 0
if let window = UIApplication.shared.keyWindow {
self.importedFileContainerView.frame = CGRect(x: 20, y: window.frame.height, width: window.frame.width - 40, height: self.frameHeight)
}
},
completion: { [weak self] finished in
self?.blackView.removeFromSuperview()
self?.importedFileContainerView.removeFromSuperview()
})
}
override init() {
super.init()
}
}
推荐答案
当您的叠加层可见时，您是否保持对 importedFileView 实例的强引用?据我测试，当目标丢失时，所有动作都会被静默忽略.
Are you keeping a strong reference to the instance of your importedFileView while your overlays are visible? As far as I tested, all actions are silently ignored when the target is lost.
例如，这不起作用:
@IBAction func someAction(_ sender: Any) {
let ifv = importedFileView()
ifv.showFormView()
//`ifv` is released at the end of this method, then your overlays are shown...
}
这有效:
let ifv = importedFileView() //keep the instance as a property of your ViewController.
@IBAction func someAction(_ sender: Any) {
ifv.showFormView()
}
<小时>
以编程方式生成的 UIViews isUserInteractionEnabled 默认为 true.您无需将其显式设置为 true.
Programmatically generated UIViews isUserInteractionEnabled is default to true. You have no need to explicitly set it to true.
顺便说一下，你最好不要把你的非UIView类命名为...View，最好让你的类型名称以大写字母开头，使您的代码对于有经验的 Swift 程序员来说更具可读性.
By the way, you'd better not name your non-UIView class as ...View, and better make your type names start with capital letter, which makes your code more readable to experienced Swift programmers.
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