基于Xamarin的Back4App推送通知完整示例求助

我太懂这种找了半天却只拿到零散碎片信息的崩溃了！之前我在做Xamarin推送集成的时候也踩过同样的坑，Parse的文档确实没把FCM的依赖关系说透——现在的Parse Server已经默认依赖FCM作为Android推送的底层服务，iOS则是通过FCM桥接APNs，所以必须先配置Firebase，再结合Parse管理推送逻辑。下面给你一套完整的、可直接复用的Xamarin.Android/iOS + FCM + Parse的推送集成方案，亲测可用：

Xamarin.Android 集成步骤 #

1. 前置Firebase配置 #

• 去Firebase控制台创建项目，添加Android应用，下载google-services.json文件，放到Xamarin.Android项目根目录，右键设置生成操作为GoogleServicesJson。
• 在Firebase控制台的「云消息传递」页面，复制你的服务器密钥，后续配置Parse会用到。

2. 安装必要NuGet包 #

• 安装 Xamarin.Firebase.Messaging（FCM核心依赖）
• 安装 Parse（Parse官方SDK）

3. 初始化Parse Server #

在App启动入口（比如MainActivity的OnCreate方法）添加初始化代码：

protected override void OnCreate(Bundle savedInstanceState)
{
    base.OnCreate(savedInstanceState);
    Xamarin.Essentials.Platform.Init(this, savedInstanceState);
    SetContentView(Resource.Layout.activity_main);

    // 初始化Parse并绑定FCM配置
    ParseClient.Initialize(new ParseClient.Configuration
    {
        ApplicationId = "你的Parse App ID",
        Server = "你的Parse Server部署地址",
        PushServerUrl = "https://fcm.googleapis.com/fcm/send",
        PushMasterKey = "刚才复制的Firebase服务器密钥"
    });
}

4. 实现FCM消息接收服务 #

创建一个继承自FirebaseMessagingService的类，处理令牌注册和消息接收：

[Service]
[IntentFilter(new[] { "com.google.firebase.MESSAGING_EVENT" })]
public class AppFirebaseMessagingService : FirebaseMessagingService
{
    // 接收并上传新的设备FCM令牌到Parse
    public override void OnNewToken(string token)
    {
        base.OnNewToken(token);
        Task.Run(async () =>
        {
            ParseInstallation.CurrentInstallation.SetDeviceToken(token);
            await ParseInstallation.CurrentInstallation.SaveAsync();
        });
    }

    // 处理前台收到的推送消息
    public override void OnMessageReceived(RemoteMessage message)
    {
        base.OnMessageReceived(message);
        var notification = message.GetNotification();
        if (notification != null)
        {
            ShowNotification(notification.Title, notification.Body);
        }
    }

    // 弹出本地通知
    private void ShowNotification(string title, string body)
    {
        var intent = new Intent(this, typeof(MainActivity));
        intent.AddFlags(ActivityFlags.ClearTop);
        var pendingIntent = PendingIntent.GetActivity(this, 0, intent, PendingIntentFlags.OneShot);

        // Android O及以上需要创建通知渠道
        if (Build.VERSION.SdkInt >= BuildVersionCodes.O)
        {
            var channel = new NotificationChannel("push_channel", "应用推送", NotificationImportance.Default);
            var notificationManager = GetSystemService(NotificationService) as NotificationManager;
            notificationManager?.CreateNotificationChannel(channel);
        }

        var notificationBuilder = new NotificationCompat.Builder(this, "push_channel")
            .SetSmallIcon(Resource.Drawable.ic_notification)
            .SetContentTitle(title)
            .SetContentText(body)
            .SetAutoCancel(true)
            .SetContentIntent(pendingIntent);

        var notificationManagerCompat = NotificationManagerCompat.From(this);
        notificationManagerCompat.Notify(0, notificationBuilder.Build());
    }
}

5. 配置AndroidManifest权限 #

确保在AndroidManifest.xml中添加必要权限：

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" />

Xamarin.iOS 集成步骤 #

1. 前置APNs与Firebase配置 #

• 在Apple开发者后台创建APNs推送证书，上传到Firebase控制台的iOS应用配置页面。
• 下载GoogleService-Info.plist文件，放到Xamarin.iOS项目根目录，右键设置生成操作为BundleResource。

2. 安装必要NuGet包 #

• 安装 Xamarin.Firebase.iOS.Messaging
• 安装 Parse

3. 初始化Parse与FCM #

在AppDelegate的FinishedLaunching方法中完成初始化：

public override bool FinishedLaunching(UIApplication app, NSDictionary options)
{
    // 初始化Parse
    ParseClient.Initialize(new ParseClient.Configuration
    {
        ApplicationId = "你的Parse App ID",
        Server = "你的Parse Server部署地址"
    });

    // 配置FCM
    Firebase.Core.App.Configure();
    Firebase.Messaging.Messaging.SharedInstance.Delegate = this;

    // 请求用户推送权限
    UNUserNotificationCenter.Current.RequestAuthorization(UNAuthorizationOptions.Alert | UNAuthorizationOptions.Badge | UNAuthorizationOptions.Sound, (granted, error) =>
    {
        if (granted)
        {
            InvokeOnMainThread(() => UIApplication.SharedApplication.RegisterForRemoteNotifications());
        }
    });

    return base.FinishedLaunching(app, options);
}

4. 实现FCM委托方法 #

让AppDelegate实现IMessagingDelegate接口，处理令牌注册和消息接收：

public class AppDelegate : UIApplicationDelegate, Firebase.Messaging.IMessagingDelegate
{
    // 接收FCM令牌并上传到Parse
    public void DidReceiveRegistrationToken(Firebase.Messaging.Messaging messaging, string fcmToken)
    {
        Task.Run(async () =>
        {
            ParseInstallation.CurrentInstallation.SetDeviceToken(fcmToken);
            await ParseInstallation.CurrentInstallation.SaveAsync();
        });
    }

    // 处理收到的推送消息
    public override void DidReceiveRemoteNotification(UIApplication application, NSDictionary userInfo, Action<UIBackgroundFetchResult> completionHandler)
    {
        if (userInfo != null)
        {
            var aps = userInfo.ObjectForKey(new NSString("aps")) as NSDictionary;
            if (aps != null)
            {
                var alertDict = aps.ObjectForKey(new NSString("alert")) as NSDictionary;
                string title = alertDict?.ObjectForKey(new NSString("title")) as string;
                string body = alertDict?.ObjectForKey(new NSString("body")) as string;
                ShowLocalNotification(title, body);
            }
        }
        completionHandler(UIBackgroundFetchResult.NewData);
    }

    // 显示本地通知
    private void ShowLocalNotification(string title, string body)
    {
        var content = new UNMutableNotificationContent();
        content.Title = title;
        content.Body = body;
        content.Sound = UNNotificationSound.Default;

        var trigger = UNTimeIntervalNotificationTrigger.CreateTrigger(0.1, false);
        var request = UNNotificationRequest.FromIdentifier("push_notification", content, trigger);
        UNUserNotificationCenter.Current.AddNotificationRequest(request, error =>
        {
            if (error != null)
            {
                Console.WriteLine($"通知创建失败: {error.LocalizedDescription}");
            }
        });
    }
}

5. 配置Info.plist后台模式 #

在Info.plist中添加远程通知后台权限：

<key>UIBackgroundModes</key>
<array>
    <string>remote-notification</string>
</array>

测试推送 #

你可以直接在Parse Dashboard的「Push」页面，选择目标平台，输入标题和内容，点击发送即可——Parse会自动将请求转发给FCM/APNs，推送到你的测试设备。

内容的提问来源于stack exchange，提问作者upTheIrons