AWS SDK for .NET 现在包括适用于 Xamarin 的 AWS Mobile SDK。本指南参考了适用于 Xamarin 的 Mobile SDK 的存档版本。

使用 SNS 接收推送通知 (Xamarin Android)

本教程介绍了如何使用 Amazon Simple Notification Service (SNS) 和适用于 .NET 和 Xamarin 的 AWS Mobile SDK 将推送通知发送到 Xamarin Android 应用程序。

项目设置

先决条件

在开始本教程前，必须先完成有关设置适用于 .NET 和 Xamarin 的 AWS Mobile SDK 的说明中的所有步骤。

设置 SNS 权限

按照设置适用于 .NET 和 Xamarin 的 AWS Mobile SDK 中第 2 步的说明操作，将下述策略附加到您应用程序的角色中。这样可为您的应用程序提供访问 SNS 的适当权限：

在 Google Cloud 上启用推送通知

首先，添加一个新的 Google API 项目：

接下来，为您的项目启用 Google Cloud Messaging (GCM) 服务：

最后，获取 API 密钥：

使用项目 ID 在 SNS 控制台中创建平台 ARN

将 SNS NuGet 程序包添加到您的项目中

按照设置适用于 .NET 和 Xamarin 的 AWS Mobile SDK中第 4 步的说明操作，将 Amazon Simple Notification Service NuGet 程序包添加到您的项目中。

创建 SNS 客户端

var snsClient = new AmazonSimpleNotificationServiceClient(credentials, region);

为您的应用程序注册远程通知

要在 Android 上注册远程通知，您必须创建一个可以接收 Google Cloud 消息的 BroadcastReceiver。请按照下方的提示，更改程序包名称：

[BroadcastReceiver(Permission = "com.google.android.c2dm.permission.SEND")]
[IntentFilter(new string[] {
      "com.google.android.c2dm.intent.RECEIVE"
}, Categories = new string[] {
      "com.amazonaws.sns" /* change to match your package */
})]
[IntentFilter(new string[] {
      "com.google.android.c2dm.intent.REGISTRATION"
}, Categories = new string[] {
      "com.amazonaws.sns" /* change to match your package */
})]
[IntentFilter(new string[] {
      "com.google.android.gcm.intent.RETRY"
}, Categories = new string[] {
      "com.amazonaws.sns" /* change to match your package */
})]
public class GCMBroadcastReceiver: BroadcastReceiver {
      const string TAG = "PushHandlerBroadcastReceiver";
      public override void OnReceive(Context context, Intent intent) {
              GCMIntentService.RunIntentInService(context, intent);
              SetResult(Result.Ok, null, null);
      }
}

[BroadcastReceiver]
[IntentFilter(new[] {
      Android.Content.Intent.ActionBootCompleted
})]
public class GCMBootReceiver: BroadcastReceiver {
      public override void OnReceive(Context context, Intent intent) {
              GCMIntentService.RunIntentInService(context, intent);
              SetResult(Result.Ok, null, null);
      }
}

下方列出的服务可用于接收 BroadcastReceiver 发来的推送通知，并在设备通知栏中显示该通知：

[Service]
 public class GCMIntentService: IntentService {
  static PowerManager.WakeLock sWakeLock;
  static object LOCK = new object();

  public static void RunIntentInService(Context context, Intent intent) {
    lock(LOCK) {
      if (sWakeLock == null) {
        // This is called from BroadcastReceiver, there is no init.
        var pm = PowerManager.FromContext(context);
        sWakeLock = pm.NewWakeLock(
        WakeLockFlags.Partial, "My WakeLock Tag");
      }
    }

    sWakeLock.Acquire();
    intent.SetClass(context, typeof(GCMIntentService));
    context.StartService(intent);
  }

  protected override void OnHandleIntent(Intent intent) {
    try {
      Context context = this.ApplicationContext;
      string action = intent.Action;

      if (action.Equals("com.google.android.c2dm.intent.REGISTRATION")) {
        HandleRegistration(intent);
      } else if (action.Equals("com.google.android.c2dm.intent.RECEIVE")) {
        HandleMessage(intent);
      }
    } finally {
      lock(LOCK) {
        //Sanity check for null as this is a public method
        if (sWakeLock != null) sWakeLock.Release();
      }
    }
  }

  private void HandleRegistration(Intent intent) {
    string registrationId = intent.GetStringExtra("registration_id");
    string error = intent.GetStringExtra("error");
    string unregistration = intent.GetStringExtra("unregistered");

    if (string.IsNullOrEmpty(error)) {
      var response = await SnsClient.CreatePlatformEndpointAsync(new CreatePlatformEndpointRequest {
        Token = registrationId,
        PlatformApplicationArn = "YourPlatformArn" /* insert your platform application ARN here */
      });
    }
  }

  private void HandleMessage(Intent intent) {
    string message = string.Empty;
    Bundle extras = intent.Extras;
    if (!string.IsNullOrEmpty(extras.GetString("message"))) {
      message = extras.GetString("message");
    } else {
      message = extras.GetString("default");
    }

    Log.Info("Messages", "message received = " + message);
    ShowNotification(this, "SNS Push", message);
    //show the message

  }

  public void ShowNotification(string contentTitle,
  string contentText) {
    // Intent
    Notification.Builder builder = new Notification.Builder(this)
      .SetContentTitle(contentTitle)
      .SetContentText(contentText)
      .SetDefaults(NotificationDefaults.Sound | NotificationDefaults.Vibrate)
      .SetSmallIcon(Resource.Drawable.Icon)
      .SetSound(RingtoneManager.GetDefaultUri(RingtoneType.Notification));

    // Get the notification manager:
    NotificationManager notificationManager = this.GetSystemService(Context.NotificationService) as NotificationManager;

    notificationManager.Notify(1001, builder.Build());
  }
}

将消息从 SNS 控制台发送到端点