如何在watchOS的SwiftUI中注册推送通知并配置相关回调？

在SwiftUI的App结构体中，没有直接对应的applicationDidFinishLaunching方法，但可以通过关联自定义UIApplicationDelegate来实现传统UIKit中的生命周期逻辑和推送通知回调，具体方案如下：

步骤1：实现自定义UIApplicationDelegate #

创建一个同时遵循UIApplicationDelegate和UNUserNotificationCenterDelegate的类，集中处理推送授权、远程注册和通知回调：

import UIKit
import UserNotifications

class AppDelegate: NSObject, UIApplicationDelegate, UNUserNotificationCenterDelegate {
    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        // 对应applicationDidFinishLaunching的初始化逻辑
        setupPushNotifications()
        return true
    }
    
    private func setupPushNotifications() {
        // 设置通知中心代理，确保能收到回调
        UNUserNotificationCenter.current().delegate = self
        
        // 请求用户通知授权
        UNUserNotificationCenter.current().requestAuthorization(options: [.badge, .sound, .alert]) { granted, error in
            if let error = error {
                print("通知授权请求失败：\(error.localizedDescription)")
            }
            if granted {
                // 授权成功后，注册远程通知以获取Device Token
                DispatchQueue.main.async {
                    UIApplication.shared.registerForRemoteNotifications()
                }
            }
        }
    }
    
    // 远程通知注册成功，获取Device Token
    func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
        let tokenString = deviceToken.map { String(format: "%02.2hhx", $0) }.joined()
        print("Device Token：\(tokenString)")
        // 此处可将Token上传至你的服务器
    }
    
    // 远程通知注册失败
    func application(_ application: UIApplication, didFailToRegisterForRemoteNotificationsWithError error: Error) {
        print("远程通知注册失败：\(error.localizedDescription)")
    }
    
    // 前台收到通知时的回调，配置通知展示方式
    func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
        // 设置前台显示通知的选项，比如横幅、声音、角标
        completionHandler([.banner, .sound, .badge])
    }
    
    // 用户点击通知后的回调，处理交互逻辑
    func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: @escaping () -> Void) {
        let notificationInfo = response.notification.request.content.userInfo
        print("用户点击通知，携带信息：\(notificationInfo)")
        
        // 处理完业务逻辑后必须调用completionHandler
        completionHandler()
    }
}

步骤2：在App结构体中关联自定义Delegate #

修改你的FieldService_Watch_AppApp，通过UIApplicationDelegateAdaptor属性绑定上面的AppDelegate：

import SwiftUI
import UserNotifications

@main
struct FieldService_Watch_AppApp: App {
    // 关联自定义AppDelegate
    @UIApplicationDelegateAdaptor(AppDelegate.self) var appDelegate
    
    @Environment(.scenePhase) private var scenePhase
    
    var body: some Scene {
        WindowGroup {
            TabView {
                TimerView()
                ContentView()
                CategoriesView()
                    .environment(.managedObjectContext, manager.defaultContext)
                ServicesView()
                    .environment(.managedObjectContext, manager.defaultContext)
                FirstView()
            }
            .tabViewStyle(PageTabViewStyle())
        }
        .onChange(of: scenePhase) { phase in
            if case .active = phase {
                Task {
                    await loadData()
                }
            }
        }
    }

    private func loadData() async {
        // 保留你原本的场景激活时的业务逻辑即可，推送授权已在AppDelegate中处理
    }
}

关键说明 #

• 推送授权时机：放在applicationDidFinishLaunching中是最优选择，App启动时即可完成授权请求，无需等待场景激活。
• 远程通知注册：必须在用户授权通知后，才能调用registerForRemoteNotifications()获取Device Token，这是APNs推送的必要前提。
• 通知回调处理：通过UNUserNotificationCenterDelegate的两个核心方法，分别控制前台通知展示规则和用户点击后的交互逻辑。

内容的提问来源于stack exchange，提问作者kunass2