如何使用默认google帐号注册GCM，无需帐号选择器选项或任何用户交互android

dependencies {
    classpath 'com.google.gms:google-services:4.3.10'
}

dependencies {
    implementation 'com.google.android.gms:play-services-gcm:17.1.0'
}

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

<application>
    <!-- ... -->
    <service
        android:name=".MyGcmListenerService"
        android:exported="false">
        <intent-filter>
            <action android:name="com.google.android.c2dm.intent.RECEIVE" />
        </intent-filter>
    </service>

    <receiver
        android:name=".MyGcmBroadcastReceiver"
        android:exported="false"
        android:permission="com.google.android.c2dm.permission.SEND">
        <intent-filter>
            <action android:name="com.google.android.c2dm.intent.RECEIVE" />
            <category android:name="your.package.name" />
        </intent-filter>
    </receiver>

    <meta-data
        android:name="com.google.android.gms.version"
        android:value="@integer/google_play_services_version" />
</application>

public class MyGcmListenerService extends GcmListenerService {
    @Override
    public void onMessageReceived(String from, Bundle data) {
        // 处理接收到的消息
    }
}

public class MyGcmBroadcastReceiver extends WakefulBroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        // 启动 GcmListenerService 处理接收到的消息
        ComponentName comp = new ComponentName(context.getPackageName(), MyGcmListenerService.class.getName());
        startWakefulService(context, (intent.setComponent(comp)));
        setResultCode(Activity.RESULT_OK);
    }
}

import com.google.android.gms.gcm.GoogleCloudMessaging;
import com.google.android.gms.iid.InstanceID;

// ...

String senderId = "YOUR_SENDER_ID"; // 用于向 GCM 服务器注册的发送者 ID

try {
    InstanceID instanceID = InstanceID.getInstance(context);
    String token = instanceID.getToken(senderId, GoogleCloudMessaging.INSTANCE_ID_SCOPE, null);
    // 将 token 发送到服务器保存，以便向该设备发送消息
} catch (IOException e) {
    e.printStackTrace();
}