SwiftUI中FamilyActivityPicker导航栏按钮不显示及双导航栏问题

核心问题原因 #

1. .navigationBarItems 在iOS 16+已被废弃，且无法作用于FamilyActivityPickerViewController（UIKit原生控制器），导致按钮不显示。
2. 外层嵌套SwiftUI的NavigationStack会与FamilyActivityPicker自身的UIKit导航栏冲突，出现双导航栏。

正确实现方式 #

通过UIViewControllerRepresentable封装FamilyActivityPicker时，直接使用UIKit的导航控制器自定义按钮，避免与SwiftUI导航组件冲突：

1. 封装带自定义导航按钮的FamilyActivityPicker

import SwiftUI
import ScreenTime

struct FamilyActivityPickerView: UIViewControllerRepresentable {
    @Binding var isPresented: Bool
    let onSelectionConfirmed: ([ActivitySelectionItem]) -> Void
    
    func makeUIViewController(context: Context) -> UINavigationController {
        let picker = FamilyActivityPickerViewController()
        picker.delegate = context.coordinator
        
        // 添加取消按钮
        picker.navigationItem.leftBarButtonItem = UIBarButtonItem(
            barButtonSystemItem: .cancel,
            target: context.coordinator,
            action: #selector(context.coordinator.onCancelTapped)
        )
        
        // 添加完成按钮
        picker.navigationItem.rightBarButtonItem = UIBarButtonItem(
            barButtonSystemItem: .done,
            target: context.coordinator,
            action: #selector(context.coordinator.onDoneTapped)
        )
        
        // 用UIKit导航控制器承载picker，确保导航栏正常显示
        return UINavigationController(rootViewController: picker)
    }
    
    func updateUIViewController(_ uiViewController: UINavigationController, context: Context) {}
    
    func makeCoordinator() -> Coordinator {
        Coordinator(parent: self)
    }
    
    class Coordinator: NSObject, FamilyActivityPickerViewControllerDelegate {
        private let parent: FamilyActivityPickerView
        
        init(parent: FamilyActivityPickerView) {
            self.parent = parent
        }
        
        @objc func onCancelTapped() {
            parent.isPresented = false
        }
        
        @objc func onDoneTapped() {
            guard let picker = parent.makeUIViewController(context: Context()).topViewController as? FamilyActivityPickerViewController else {
                parent.isPresented = false
                return
            }
            parent.onSelectionConfirmed(picker.selectedItems ?? [])
            parent.isPresented = false
        }
        
        // 实现picker代理的默认方法（可选兜底）
        func familyActivityPickerViewControllerDidFinish(_ controller: FamilyActivityPickerViewController) {
            parent.isPresented = false
        }
        
        func familyActivityPickerViewControllerDidCancel(_ controller: FamilyActivityPickerViewController) {
            parent.isPresented = false
        }
    }
}

2. 在SwiftUI视图中调用封装好的Picker

直接用.sheet或.fullScreenCover展示，无需嵌套SwiftUI的NavigationStack：

struct MainView: View {
    @State private var showActivityPicker = false
    @State private var selectedActivities: [ActivitySelectionItem] = []
    
    var body: some View {
        VStack(spacing: 20) {
            Button("选择限制活动") {
                showActivityPicker = true
            }
            
            if !selectedActivities.isEmpty {
                Text("已选中\(selectedActivities.count)项活动")
            }
        }
        .sheet(isPresented: $showActivityPicker) {
            FamilyActivityPickerView(
                isPresented: $showActivityPicker,
                onSelectionConfirmed: { items in
                    selectedActivities = items
                }
            )
        }
    }
}

关键说明 #

• 用UIKit的UINavigationController承载FamilyActivityPickerViewController，确保导航栏属于同一层级，避免双栏冲突。
• 直接通过UIBarButtonItem添加按钮，绑定到Coordinator的方法处理取消/完成逻辑，同时利用FamilyActivityPicker的代理方法做兜底。

内容的提问来源于stack exchange，提问作者sudoExclamationExclamation