我搜索了很多关于当应用程序处于后台或关闭时通知的信息。顺便说一下，我正在使用Firebase Cloud Messaging。对我没用。我使用了Android设置，当应用程序在前台或手机未锁定时，收到通知.

• 安装后，令牌将正确打印并订阅主题。
• 当我发送通知时，应用程序活跃在前台（因此屏幕解锁并显示应用程序），我收到通知和标题，如onMessageReceived中所述。
• 当我发送通知时，应用程序未显示但仍在最近的应用程序中，屏幕解锁我收到通知，标题和消息如notification payload所述。
• 当我在应用程序未显示但仍在最近的应用程序中并且屏幕锁定时发送通知时，没有收到任何内容。
• 当我在应用程序*关闭并从最近的应用程序中删除时发送通知时，没有收到任何通知。

如何更改此功能，使应用程序始终收到通知，即使关闭或手机已锁定？
Ps.我读到了关于受保护应用程序的打瞌睡方式，即使当我把我的应用程序与受保护的我什么也没有收到。我正在测试华为P8 Lite。

AndroidManifest

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.CALL_PHONE" />
<uses-permission android:name="android.permission.WRITE_SETTINGS"/>
<uses-permission android:name="android.permission.VIBRATE" />
<uses-permission android:name="android.permission.WAKE_LOCK" />

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/AppTheme" >
    <activity android:name=".activities.MainActivity"
        android:configChanges="orientation"
        android:screenOrientation="portrait">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <service
        android:name=".services.MyAppFirebaseMessagingService"
        android:enabled="true"
        android:exported="true">
        <intent-filter>
            <action android:name="com.google.firebase.MESSAGING_EVENT"/>
        </intent-filter>
    </service>
    <service
        android:name=".services.FirebaseIDService"
        android:enabled="true"
        android:exported="true">
        <intent-filter>
            <action android:name="com.google.firebase.INSTANCE_ID_EVENT"/>
        </intent-filter>
    </service>
    <receiver android:name=".services.NotificationReceiver" />
</application>

Gradle

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    testCompile 'junit:junit:4.12'
    compile 'com.google.firebase:firebase-core:9.2.0'
    compile 'com.google.firebase:firebase-messaging:9.2.0'
}

apply plugin: 'com.google.gms.google-services'

FirebaseMessagingService

public class MyAppFirebaseMessagingService extends FirebaseMessagingService {
    private static final String TAG = "FCM Service";

    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {
        // TODO: Handle FCM messages here.
        // If the application is in the foreground handle both data and notification messages here.
        // Also if you intend on generating your own notifications as a result of a received FCM
        // message, here is where that should be initiated.
        Log.d(TAG, "From: " + remoteMessage.getFrom());
        Log.d(TAG, "Notification Message Body: " + remoteMessage.getNotification().getBody());

        showNotification(getApplicationContext());
    }

    public static void showNotification(Context context){
        Intent intent = new Intent(context, MainActivity.class);
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        PendingIntent pendingIntent = PendingIntent.getActivity(context, 0 /* Request code */, intent,
            PendingIntent.FLAG_ONE_SHOT);

        Uri defaultSoundUri= RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(context)
            .setSmallIcon(R.drawable.ic_launcher)
            .setContentTitle("FCM Message")
            .setContentText("FCM Body")
            .setAutoCancel(true)
            .setSound(defaultSoundUri)
            .setPriority(Notification.PRIORITY_MAX)
            .setContentIntent(pendingIntent);

        NotificationManager notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);

        notificationManager.notify(0, notificationBuilder.build());
    }
}

FirebaseInstanceIDService

public class FirebaseIDService extends FirebaseInstanceIdService {

    private static final String TAG = "FirebaseIDService";

    @Override
    public void onTokenRefresh() {
        // Get updated InstanceID token.
        String refreshedToken = FirebaseInstanceId.getInstance().getToken();
        Log.d(TAG, "Refreshed token: " + refreshedToken);

        System.out.println("Devicetoken: " + refreshedToken);

        FirebaseMessaging.getInstance().subscribeToTopic("/topics/myapp");

        // TODO: Implement this method to send any registration to your app's servers.
        sendRegistrationToServer(refreshedToken);
     }

    /**
     * Persist token to third-party servers.
     *
     * Modify this method to associate the user's FCM InstanceID token with any server-side account
     * maintained by your application.
     *
     * @param token The new token.
     */
    private void sendRegistrationToServer(String token) {
         // Add custom implementation, as needed.
    }
}

通知负载

{
    "to": "/topics/mytopic",
    "priority": "high",
    "notification": {
        "sound": "default",
        "badge": "1",
        "body": "the body text",
        "title": "title text"
     },
     "data": {
         "id": "id",
         "channel": "channel"
     }
}

编辑-添加WakeFulBroadcastReceiver代码

public class NotificationReceiver extends WakefulBroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {

        // cancel any further alarms
        AlarmManager alarmMgr = (AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
        PendingIntent alarmIntent = PendingIntent.getBroadcast(context, 0, intent, PendingIntent.FLAG_CANCEL_CURRENT);
        alarmMgr.cancel(alarmIntent);
        completeWakefulIntent(intent);

        // start the GcmTaskService
        MyAppFirebaseMessagingService.showNotification(context);
    }
}

更新有效负载

如果我将我的有效负载更改为像这样的评论中建议的方式，它仍然不起作用。也许这与我正在安装Android 6.0.1进行测试的华为P8 Lite有关。

{
    "to": "/topics/mytopic",
    "priority": "high",
    "data": {
        "sound": "default",
        "badge": "1",
        "body": "the body text",
        "title": "title text"
    }
}

更新2.0

我已经在多个设备和版本上进行了测试。在Android 5的设备上，它工作正常，也没有应用程序打开和屏幕锁定。唯一不工作的设备是我自己的华为P8 Lite。我还是不明白为什么那个不管用。