Android推送通知 - Parse.com API - 不工作？

Question

这是应用程序代码：

import android.app.Application;
import android.util.Log;

import com.ghostriley.sgt.ghostchat.UI.MainActivity;
import com.parse.Parse;
import com.parse.ParseException;
import com.parse.ParseInstallation;
import com.parse.ParseObject;
import com.parse.ParseAnalytics;
import com.parse.ParsePush;
import com.parse.ParsePushBroadcastReceiver;
import com.parse.PushService;
import com.parse.SaveCallback;



public class GhostChatApplication extends Application {
    @Override
    public void onCreate(){
        super.onCreate();

        Parse.initialize(this, "P0zIagKQvEGdopuoLZuucgzC7H4oz64U7GZkGe1n", "mT15MV8OFEMTDNQaGU5XdLHTXMsNxnUxJdXVp4O3");    
        ParseInstallation.getCurrentInstallation().saveInBackground();

    }

}

虽然在Docs中没有提到订阅该频道，但是当我测试时，我确实成功订阅了。如果我在其中放入一些随机字符串将无法工作，所以可能“testNotification”恰好是正确的。这是清单：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.ghostriley.sgt.ghostchat" >

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <service android:name="com.parse.PushService" />
    <receiver android:name="com.parse.ParsePushBroadcastReceiver"
        android:exported="false">
        <intent-filter>
            <action android:name="com.parse.push.intent.RECEIVE" />
            <action android:name="com.parse.push.intent.DELETE" />
            <action android:name="com.parse.push.intent.OPEN" />
        </intent-filter>
    </receiver>
    <receiver android:name="com.parse.GcmBroadcastReceiver"
        android:permission="com.google.android.c2dm.permission.SEND">
        <intent-filter>
            <action android:name="com.google.android.c2dm.intent.RECEIVE" />
            <action android:name="com.google.android.c2dm.intent.REGISTRATION" />
            <category android:name="com.ghostriley.sgt.ghostchat" />
        </intent-filter>
    </receiver>

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.WAKE_LOCK" />
    <uses-permission android:name="android.permission.VIBRATE" />
    <uses-permission android:name="android.permission.GET_ACCOUNTS" />
    <uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" />
    <permission android:protectionLevel="signature"
        android:name="com.ghostriley.sgt.ghostchat.C2D_MESSAGE" />
    <uses-permission android:name="com.ghostriley.sgt.ghostchat.permission.C2D_MESSAGE" />

    <uses-feature
        android:name="android.hardware.camera"
        android:required="true" />

    <application
        android:name=".GhostChatApplication"
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >

            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value="com.ghostriley.sgt.ghostchat.UI.MainActivity" />
        </activity>

    </application>

</manifest>

我删除了应用程序标签以使代码变小。