问Android GoogleApiClient:无法连接

EN

mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addApi(Games.API).addScope(Games.SCOPE_GAMES)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .build();

@Override
protected void onStart() {
    super.onStart();
    if( mGoogleApiClient != NULL )
        mGoogleApiClient.connect()
}

private void openAchievements() {
  if( !mGoogleApiClient.isConnected() ) // always false
      return;

  startActivityForResult(Games.Achievements.getAchievementsIntent(mGoogleApiClient), REQUEST_ACHIEVEMENTS);
}

@Override
public void onConnected(Bundle bundle) {
    Log.e("DEBUG", "Connected!");
}

@Override
public void onConnectionSuspended(int i) {
    Log.e("DEBUG", "connection suspended");
}

@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
    Log.e("DEBUG", "connection failed");
}

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

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