Android can't extend Firebase Messaging Servic

问题:

I am trying to implement Firebase Cloud Messaging in my application, I had implemented all settings to use this service, but when I try to extend FirebaseMessagingService in my class it gives me error and it can't find it at all, I can't even import com.google.firebase.messaging.FirebaseMessagingService as shown in the picture:

I had added all the code required: I added this to app gradle

compile 'com.google.firebase:firebase-core:9.4.0' 
apply plugin: 'com.google.gms.google-services'

and this to the module gradle:

classpath 'com.google.gms:google-services:3.0.0'

this is the manifest code:

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

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <service
        android:name=".MyFirebaseMessagingService">
        <intent-filter>
            <action android:name="com.google.firebase.MESSAGING_EVENT"/>
        </intent-filter>
    </service>
    <service
        android:name=".MyFirebaseInstanceIDService">
        <intent-filter>
            <action android:name="com.google.firebase.INSTANCE_ID_EVENT"/>
        </intent-filter>
    </service>
</application>

and I added the google json file to the app. So if anybody can help me please

回答1:

If you want to use messaging, you have to add the messaging module. Right now you only added the core module.

So go ahead and include

compile 'com.google.firebase:firebase-messaging:9.4.0'

All the available modules can be found at the bottom of https://firebase.google.com/docs/android/setup