避免在 dismiss Sheet 后快速返回 NavigationView 上层视图导致的应用锁死

disableNavigationViewGesture.swift

/*
当在 NavigationView 非根视图中显示 sheet 时，在 dismiss Sheet 后快速用手势（ 从左向右 ）返回上层视图会导致整个 UI 锁死，
应用从此无法响应。写了个 ViewModifer ，来避免这种情况
*/
public extension Notification.Name {
    static let disableNavigationViewGesture = Notification.Name("disableNavigationViewGesture")
}

public struct NavigationViewGestureMaskModifier: ViewModifier {
    @State private var enable = false
    public func body(content: Content) -> some View {
        content
            .overlay(
                VStack {
                    if enable {
                        Color.white.opacity(0.001)
                    }
                }
            )
            .onReceive(NotificationCenter.default.publisher(for: .disableNavigationViewGesture)) { notification in
                guard let enable = notification.object as? Bool else { return }
                self.enable = enable
            }
    }
}

public extension View {
    func disableGestureWhenSheetPopup() -> some View {
        modifier(NavigationViewGestureMaskModifier())
    }
}


public struct CallDisableGestureWhenSheetPopup {
    public func callAsFunction(_ disableGesture: Bool) {
        NotificationCenter.default.post(name: .disableNavigationViewGesture, object: disableGesture)
    }
}

struct CallDisableGestureWhenSheetPopupKey: EnvironmentKey {
    static var defaultValue = CallDisableGestureWhenSheetPopup()
}

public extension EnvironmentValues {
    var disableNavigationViewGesture: CallDisableGestureWhenSheetPopup {
        self[CallDisableGestureWhenSheetPopupKey.self]
    }
}

struct RootView: View {
    var body: some View {
        NavigationStack {
            NavigationLink("Hello", destination: DestinationView())
        }
        .disableGestureWhenSheetPopup()
    }
}

struct DestinationView: View {
    @State var popUp = false
    @Environment(\.disableNavigationViewGesture) var disable
    var body: some View {
        Button("Show Sheet") {
            disable(true)
            popUp.toggle()
        }
        .sheet(isPresented: $popUp, onDismiss: {
            disable(false)
        }) {
            Text("HI")
        }
    }
}