Swift 3：UIScrollView 和（禁用）手势识别器

Posted 2023-03-12

【中文标题】Swift 3：UIScrollView 和（禁用）手势识别器

【英文标题】：Swift 3: UIScrollView and (disabling) Gesture Recognizers

【发布时间】：2016-11-27 20:27:48

【问题描述】：

我在 swift 3 中，我有一个类是 UIScrollView 的子类。这里是：

import SpriteKit

/// Scroll direction
enum ScrollDirection 
    case vertical
    case horizontal


class CustomScrollView: UIScrollView 

    // MARK: - Static Properties

    /// Touches allowed
    static var disabledTouches = false

    /// Scroll view
    private static var scrollView: UIScrollView!

    // MARK: - Properties

    /// Current scene
    private let currentScene: SKScene

    /// Moveable node
    private let moveableNode: SKNode

    /// Scroll direction
    private let scrollDirection: ScrollDirection

    /// Touched nodes
    private var nodesTouched = [AnyObject]()

    // MARK: - Init
    init(frame: CGRect, scene: SKScene, moveableNode: SKNode, scrollDirection: ScrollDirection) 
        self.currentScene = scene
        self.moveableNode = moveableNode
        self.scrollDirection = scrollDirection
        super.init(frame: frame)

        CustomScrollView.scrollView = self
        self.frame = frame
        delegate = self
        indicatorStyle = .white
        isScrollEnabled = true
        isUserInteractionEnabled = true
        //canCancelContentTouches = false
        //self.minimumZoomScale = 1
        //self.maximumZoomScale = 3

        if scrollDirection == .horizontal 
            let flip = CGAffineTransform(scaleX: -1,y: -1)
            transform = flip
        
    

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

    /// Began
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) 
        print("begin " + String(CustomScrollView.disabledTouches))

        for touch in touches 
            let location = touch.location(in: currentScene)
            guard !CustomScrollView.disabledTouches else  return 

            /// Call touches began in current scene
            currentScene.touchesBegan(touches, with: event)

            /// Call touches began in all touched nodes in the current scene
            nodesTouched = currentScene.nodes(at: location)
            for node in nodesTouched 
                node.touchesBegan(touches, with: event)
            
        
    

    /// Moved
    override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) 
        print("moved " + String(CustomScrollView.disabledTouches))

        for touch in touches 
            let location = touch.location(in: currentScene)

            guard !CustomScrollView.disabledTouches else  return 

            /// Call touches moved in current scene
            currentScene.touchesMoved(touches, with: event)

            /// Call touches moved in all touched nodes in the current scene
            nodesTouched = currentScene.nodes(at: location)
            for node in nodesTouched 
                node.touchesMoved(touches, with: event)
            
        
    

    /// Ended
    override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) 

        for touch in touches 
            let location = touch.location(in: currentScene)

            guard !CustomScrollView.disabledTouches else  return 

            /// Call touches ended in current scene
            currentScene.touchesEnded(touches, with: event)

            /// Call touches ended in all touched nodes in the current scene
            nodesTouched = currentScene.nodes(at: location)
            for node in nodesTouched 
                node.touchesEnded(touches, with: event)
            
        
    

    /// Cancelled
    override func touchesCancelled(_ touches: Set<UITouch>, with event: UIEvent?) 

        print("cancelled " + String(CustomScrollView.disabledTouches))
        for touch in touches 
            let location = touch.location(in: currentScene)

            guard !CustomScrollView.disabledTouches else  return 

            /// Call touches cancelled in current scene
            currentScene.touchesCancelled(touches, with: event)

            /// Call touches cancelled in all touched nodes in the current scene
            nodesTouched = currentScene.nodes(at: location)
            for node in nodesTouched 
                node.touchesCancelled(touches, with: event)
            
        
    


// MARK: - Touch Controls
extension CustomScrollView 

    /// Disable
    class func disable() 
        CustomScrollView.scrollView?.isUserInteractionEnabled = false
        CustomScrollView.disabledTouches = true
    

    /// Enable
    class func enable() 
        CustomScrollView.scrollView?.isUserInteractionEnabled = true
        CustomScrollView.disabledTouches = false
    


// MARK: - Delegates
extension CustomScrollView: UIScrollViewDelegate 

    func scrollViewDidScroll(_ scrollView: UIScrollView) 

        if scrollDirection == .horizontal 
            moveableNode.position.x = scrollView.contentOffset.x
         else 
            moveableNode.position.y = scrollView.contentOffset.y
        
    

它的主要功能是创建一个可滚动的菜单，并且大部分情况下它都可以工作。我在 GameScene 中创建了它的一个对象，它的工作原理是当注册触摸时，会调用 CustomScrollView 中覆盖的触摸函数（touchBegan、touchMoved 等），然后调用 GameScene 中的触摸函数。这确实发生了，菜单滚动正常，并且调用了 GameScene 的方法。

关键是我的覆盖函数（和 GameScene 的）只有在您水平滑动时才会被调用。当您向上或向下滑动（超过一定程度）时，菜单仍会滚动，但我认为正在调用的是 UIScrollView 的触摸方法。

当你垂直滑动时，我的 touchCancelled 方法被调用，这让我认为这与 UIScrollView 的手势识别器（我认为是平移/拖动识别器）在不应该触发时触发有关。

是这样吗？如果是这样，我可以禁用识别器吗？如果可以，我应该吗？附带说明一下，这是实现 UIScrollView 以便仍然调用 GameScene 的触摸方法的最佳（或至少是可接受的）方法吗？

【参考方案1】：

如果需要同时识别冲突的手势识别器，可以使用gestureRecognizer(_:shouldRecognizeSimultaneouslyWith:)，