如何在我的应用程序未运行时接收通知？

import UserNotifications

// 请求用户权限
UNUserNotificationCenter.current().requestAuthorization(options: [.alert, .badge, .sound]) { granted, error in
    if granted {
        print("User granted permission for notifications")
    } else {
        print("User did not grant permission for notifications")
    }
}

// 配置通知内容
let content = UNMutableNotificationContent()
content.title = "New Message"
content.body = "You have a new message from John Doe"
content.sound = UNNotificationSound.default

// 配置触发器
let trigger = UNTimeIntervalNotificationTrigger(timeInterval: 5, repeats: false)

// 创建通知请求
let request = UNNotificationRequest(identifier: "newMessage", content: content, trigger: trigger)

// 添加通知请求到UNUserNotificationCenter
UNUserNotificationCenter.current().add(request) { error in
    if let error = error {
        print("Error adding notification: \(error.localizedDescription)")
    } else {
        print("Notification added successfully")
    }
}

import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.content.Context;
import android.os.Build;
import androidx.core.app.NotificationCompat;

public class NotificationHelper {
    private static final String CHANNEL_ID = "default_channel_id";
    private static final String CHANNEL_NAME = "Default Channel";

    public static void createNotificationChannel(Context context) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            NotificationChannel channel = new NotificationChannel(
                    CHANNEL_ID,
                    CHANNEL_NAME,
                    NotificationManager.IMPORTANCE_DEFAULT
            );
            NotificationManager manager = context.getSystemService(NotificationManager.class);
            manager.createNotificationChannel(channel);
        }
    }

    public static void sendNotification(Context context, String title, String message) {
        NotificationCompat.Builder builder = new NotificationCompat.Builder(context, CHANNEL_ID)
                .setSmallIcon(R.drawable.ic_notification)
                .setContentTitle(title)
                .setContentText(message)
                .setPriority(NotificationCompat.PRIORITY_DEFAULT);

        NotificationManagerCompat notificationManager = NotificationManagerCompat.from(context);
        notificationManager.notify(1, builder.build());
    }
}