在 SwiftUI TabView 中禁用滑动手势

试图实施一个TabView with PageTabView风格SwiftUI，其中导航仅以编程方式完成，并且所有滑动手势均被禁用。

这个解决方案 https://stackoverflow.com/questions/63168014/swiftui-2-0-tabview-disable-swipe-to-change-page仅部分有效 - 如果您在选择更改时点击屏幕，它仍然会干扰过渡并导致奇怪的效果。此外，如果您用两根手指滚动，该手势仍然会记录下来。我需要一个完全禁用滑动手势的解决方案。

Code:

struct PageViewTest: View {
    @State var selection: Int = 1
    
    var body: some View {
        ZStack {
            Color.green.ignoresSafeArea()
            
            TabView(selection: $selection) {
                Color.red
                    .tag(1)
                    .gesture(DragGesture())
                
                Color.blue
                    .tag(2)
                    .gesture(DragGesture())
                
                Color.yellow
                    .tag(3)
                    .gesture(DragGesture())
            }
            .tabViewStyle(PageTabViewStyle(indexDisplayMode: .never))
            .animation(.linear, value: selection)
            
            VStack {
                Spacer()
                Button(action: {
                    selection = selection == 3 ? 1 : selection + 1
                }) {
                    Text("next")
                        .foregroundColor(.white)
                        .font(.title)
                }
            }
        }
    }
}

setting .disabled(true) to the TabView解决了这个问题，但是所有子视图都不再具有交互性。

这个答案 https://stackoverflow.com/a/59371145/5668378允许在 SwiftUI 中使用自定义手势识别器创建覆盖层。 然后我们需要创建一个不允许手势启动的委托。

所以代码是：

import SwiftUI
import UIKit


struct ContentView: View {
    @State var selection: Int = 1
    let numTabs = 3
    let minDragTranslationForSwipe: CGFloat = 5000

    var body: some View {
        ZStack {
            Color.green.ignoresSafeArea()
            
            TabView(selection: $selection) {
                Color.red
                    .tag(1)
                Color.blue
                    .tag(2)
                Color.yellow
                    .tag(3)
            }
            .tabViewStyle(PageTabViewStyle(indexDisplayMode: .never))
            .animation(.linear, value: selection)
                .overlay(TouchesHandler())
            
            VStack {
                Spacer()
                Button(action: {
                    selection = selection == 3 ? 1 : selection + 1
                }) {
                    Text("next")
                        .foregroundColor(.white)
                        .font(.title)
                }
            }
        }

    }
}

//just a dummy
class MySwipeGesture: UISwipeGestureRecognizer {

    @objc func noop() {}

    init(target: Any?) {
        super.init(target: target, action: #selector(noop))
    }
}

//this delegate effectively disables the gesure
class MySwipeGestureDelegate: NSObject, UIGestureRecognizerDelegate {
    func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
        false
    }
}

//and the overlay inspired by the answer from the link above
struct TouchesHandler: UIViewRepresentable {

    func makeUIView(context: UIViewRepresentableContext<TouchesHandler>) -> UIView {
        let view = UIView(frame: .zero)
        view.isUserInteractionEnabled = true
        view.addGestureRecognizer(context.coordinator.makeGesture())
        return view;
    }

    func updateUIView(_ uiView: UIView, context: UIViewRepresentableContext<TouchesHandler>) {
    }

    func makeCoordinator() -> Coordinator {
        return Coordinator()
    }

    class Coordinator {
        var delegate: UIGestureRecognizerDelegate = MySwipeGestureDelegate()
        func makeGesture() -> MySwipeGesture {
            delegate = MySwipeGestureDelegate()
            let gr = MySwipeGesture(target: self)
            gr.delegate = delegate
            return gr
        }
    }
    typealias UIViewType = UIView
}