Swift hitTest:point withEvent检测子视图

Question

我正在尝试使用 hitTest 检测子视图何时被点击。这是我的实现：

class MyViews:UIView {
    override init (frame : CGRect) {
        super.init(frame : frame)
    }
    
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
    }
    
    override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
        
        for subview in self.subviews.reversed() {
            let subPoint = subview.convert(point, from:self);
            
            if let result = subview.hitTest(subPoint, with:event) {
                return result;
            }
        }
        return nil
    }
}

这是我添加子视图的方式：

    override func viewDidLoad() {
        super.viewDidLoad()
        let gesture = UITapGestureRecognizer(target: self, action: #selector(doSomethingHere(_:)))
        
        let blueView = MyViews(frame: CGRect(origin: CGPoint(x: 38.0, y: 231.0), size: CGSize(width: 335.0, height: 444.0)))
        blueView.tag = 100
        blueView.isUserInteractionEnabled = true
        blueView.backgroundColor = .blue
        blueView.addGestureRecognizer(gesture)
        view.addSubview(blueView)
        
        let grey = MyViews(frame: CGRect(origin: CGPoint(x: 38.0, y: 20.0 ), size: CGSize(width: 279, height: 203.0)))
        grey.tag = 200
        grey.backgroundColor = .gray
        grey.isUserInteractionEnabled = true
        grey.addGestureRecognizer(gesture)
        blueView.addSubview(grey)
        
        let white = MyViews(frame: CGRect(origin: CGPoint(x: 56.0 , y: 17.0 ), size: CGSize(width: 182.0, height: 92)))
        white.tag = 300
        white.isUserInteractionEnabled = true
        white.addGestureRecognizer(gesture)
        grey.addSubview(white)
        
        let result = blueView.hitTest(CGPoint(x: 157.5, y: 149.0), with: nil)
        print(result ?? "no result")

    }

我正在模拟这条线上的触摸let result = blueView.hitTest(CGPoint(x: 157.5, y: 149.0), with: nil)

但是这个函数的响应：

    override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
        
        for subview in self.subviews.reversed() {
            let subPoint = subview.convert(point, from:self);
            
            if let result = subview.hitTest(subPoint, with:event) {
                return result;
            }
        }
        return nil
    }

它总是为零。我不明白为什么它应该返回白色视图。

你们知道为什么这个函数没有返回正确的视图吗？

非常感谢你的帮助。

Answer 1

您的 hitTest 似乎从不检查该点是否在视图中。试一试：

    override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
    // if there are subviews, step through them
    // if the subview contains the point, call hitTest on the subview to see if the subview's subviews contain the point
    // if they do, return the result,
    // if they don't, return the subview that does contain the point.
    for subview in self.subviews.reversed() {
        let subPoint = subview.convert(point, from:self)
        if subview.point(inside: subPoint, with: event) == true {
            if let result = subview.hitTest(subPoint, with: event) {
                return result
            } else {
                return subview
            }
        }
    }
    // none of the subviews contain the point,(or there are no subviews) does the current view contain the point?
    // if yes, return self. otherwise, return nil
    if self.point(inside: point, with: event) == true {
        return self
    } else {
        return nil
    }
}

Swift hitTest:point withEvent检测子视图

Swift hitTest:point withEvent to detect subview

iphone

uiview

ios

swift

xcode12