我将保罗的回答与苹果公司过时的例子结合起来，创造了一种检测任意数量的触摸的方法。

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import Foundation
import UIKit

class NFingerGestureRecognizer: UIGestureRecognizer {

    var tappedCallback: (UITouch, CGPoint?) -> Void

    var touchViews = [UITouch:CGPoint]()

    init(target: Any?, tappedCallback: @escaping (UITouch, CGPoint?) -> ()) {
        self.tappedCallback = tappedCallback
        super.init(target: target, action: nil)
    }

    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent) {
        for touch in touches {
            let location = touch.location(in: touch.view)
            // print("Start: (\(location.x)/\(location.y))")
            touchViews[touch] = location
            tappedCallback(touch, location)
        }
    }

    override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent) {
        for touch in touches {
            let newLocation = touch.location(in: touch.view)
            // let oldLocation = touchViews[touch]!
            // print("Move: (\(oldLocation.x)/\(oldLocation.y)) -> (\(newLocation.x)/\(newLocation.y))")
            touchViews[touch] = newLocation
            tappedCallback(touch, newLocation)
        }
    }

    override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent) {
        for touch in touches {
            // let oldLocation = touchViews[touch]!
            // print("End: (\(oldLocation.x)/\(oldLocation.y))")
            touchViews.removeValue(forKey: touch)
            tappedCallback(touch, nil)
        }
    }

}

你需要把它包装，把它作为一个 SwiftUI 组件使用：UIViewRepresentable

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import Foundation
import SwiftUI

struct TapView: UIViewRepresentable {

    var tappedCallback: (UITouch, CGPoint?) -> Void

    func makeUIView(context: UIViewRepresentableContext<TapView>) -> TapView.UIViewType {
        let v = UIView(frame: .zero)
        let gesture = NFingerGestureRecognizer(target: context.coordinator, tappedCallback: tappedCallback)
        v.addGestureRecognizer(gesture)
        return v
    }
    
    func updateUIView(_ uiView: UIView, context: UIViewRepresentableContext<TapView>) {
        // empty
    }

}

如何在 SwiftUI 中使用的小例子：TapView

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var body: some View {
    guard let img = UIImage(named: "background.png") else {
        fatalError("Unable to load image")
    }
    return GeometryReader { geometry in
        ZStack {
            Image(uiImage: img)
                    .resizable()
                    .aspectRatio(geometry.size, contentMode: .fill)
                    .edgesIgnoringSafeArea(.all)


            TapView { touch, optLocation in
                // touch can be used as a dictionary key.
                // optLocation is nil when the touch ends.
            }
        }
    }
}

原文地址

stackoverflow.com