同一UIView中两个UIPanGestureRecognizer能否同时触发？

核心疑问解答 #

在同一个UIView中同时触发两个UIPanGestureRecognizer完全可行，但需要精准控制触摸事件的分配逻辑，你的问题出在触摸事件的归属判定上。

当前问题原因 #

第一个手势激活后，系统会默认将后续触摸事件优先分配给已处于活跃状态的手势。即使第二个触摸点落在另一区域，由于你的shouldReceive touch方法直接返回true，没有限制每个手势只能接收对应区域的触摸，导致第二个触摸被已活跃的手势“占用”，无法触发第二个手势。

解决方案 #

通过手势代理的shouldReceive touch方法，为每个手势过滤触摸点：只让panGesture1接收视图上半区的触摸，panGesture2接收下半区的触摸。同时保留shouldRecognizeSimultaneouslyWith返回true，确保两个手势可以同时激活。

优化后的完整代码如下：

class YourViewController: UIViewController, UIGestureRecognizerDelegate {
    let panGesture1 = UIPanGestureRecognizer()
    let panGesture2 = UIPanGestureRecognizer()

    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 配置panGesture1
        panGesture1.addTarget(self, action: #selector(panGesture1Detected(_:)))
        panGesture1.delegate = self
        panGesture1.minimumNumberOfTouches = 1
        panGesture1.maximumNumberOfTouches = 1
        panGesture1.cancelsTouchesInView = false
        panGesture1.delaysTouchesBegan = false
        panGesture1.delaysTouchesEnded = true
        panGesture1.requiresExclusiveTouchType = false
        view.addGestureRecognizer(panGesture1)
        
        // 配置panGesture2
        panGesture2.addTarget(self, action: #selector(panGesture2Detected(_:)))
        panGesture2.delegate = self
        panGesture2.minimumNumberOfTouches = 1
        panGesture2.maximumNumberOfTouches = 1
        panGesture2.cancelsTouchesInView = false
        panGesture2.delaysTouchesBegan = false
        panGesture2.delaysTouchesEnded = true
        panGesture2.requiresExclusiveTouchType = false
        view.addGestureRecognizer(panGesture2)
    }

    // 允许两个手势同时识别
    func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
        return true
    }

    // 限制手势仅在对应区域开始触发
    func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
        let touchY = gestureRecognizer.location(in: view).y
        let midY = view.bounds.midY
        
        if gestureRecognizer == panGesture1 {
            return touchY < midY
        } else if gestureRecognizer == panGesture2 {
            return touchY > midY
        }
        return false
    }

    // 过滤每个手势能接收的触摸点
    func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldReceive touch: UITouch) -> Bool {
        let touchY = touch.location(in: view).y
        let midY = view.bounds.midY
        
        if gestureRecognizer == panGesture1 {
            return touchY < midY
        } else if gestureRecognizer == panGesture2 {
            return touchY > midY
        }
        return false
    }

    // 手势触发回调
    @objc func panGesture1Detected(_ gesture: UIPanGestureRecognizer) {
        // 处理上半区拖拽逻辑
    }

    @objc func panGesture2Detected(_ gesture: UIPanGestureRecognizer) {
        // 处理下半区拖拽逻辑
    }
}

对临时思路的评估 #

添加空UIView分隔区域的方法可行：将上半区的空视图绑定panGesture1，下半区绑定panGesture2，系统会自动根据触摸点所在视图分配事件，无需复杂的代理逻辑。但这种方式会增加视图层级，如果你希望保持视图结构简洁，使用上述代理方法更优。

内容的提问来源于stack exchange，提问作者Gizmodo