Android - 连接到Google Play服务API

Question

我是Android编程的新手，我正在尝试使用谷歌播放服务。我正在逐步关注this guide。

    public class MainActivity extends AppCompatActivity implements
            GoogleApiClient.ConnectionCallbacks,
            GoogleApiClient.OnConnectionFailedListener  {

        private static int RC_SIGN_IN = 9001;
        private boolean mResolvingConnectionFailure = false;
        private boolean mAutoStartSignInflow = true;
        private boolean mSignInClicked = false;
        private GoogleApiClient mGoogleApiClient;
        boolean mExplicitSignOut = false;
        boolean mInSignInFlow = false; 
@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // Create the Google Api Client with access to the Play Games services
        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .addApi(Games.API).addScope(Games.SCOPE_GAMES)
                // add other APIs and scopes here as needed
                .build();

...
...
}



    @Override
    protected void onStart() {
        super.onStart();
            mGoogleApiClient.connect();

    }
    @Override
    protected void onStop() {
        super.onStop();
        mGoogleApiClient.disconnect();
    }

    @Override
    public void onConnected(Bundle connectionHint) {
        // The player is signed in. Hide the sign-in button and allow the
        // player to proceed.
    }

    @Override
    public void onConnectionFailed(ConnectionResult connectionResult) {
        if (mResolvingConnectionFailure) {
            // already resolving
            return;
        }

        // if the sign-in button was clicked or if auto sign-in is enabled,
        // launch the sign-in flow
        if (mSignInClicked || mAutoStartSignInflow) {
            mAutoStartSignInflow = false;
            mSignInClicked = false;
            mResolvingConnectionFailure = true;

            // Attempt to resolve the connection failure using BaseGameUtils.
            // The R.string.signin_other_error value should reference a generic
            // error string in your strings.xml file, such as "There was
            // an issue with sign-in, please try again later."
            if (!BaseGameUtils.resolveConnectionFailure(this,
                    mGoogleApiClient, connectionResult,
                    RC_SIGN_IN, R.string.signin_other_error)) {
                mResolvingConnectionFailure = false;
            }
        }

        // Put code here to display the sign-in button
    }

    @Override
    public void onConnectionSuspended(int i) {
        // Attempt to reconnect
        mGoogleApiClient.connect();
    }
    protected void onActivityResult(int requestCode, int resultCode,
                                    Intent intent) {
        if (requestCode == RC_SIGN_IN) {
            mSignInClicked = false;
            mResolvingConnectionFailure = false;
            if (resultCode == RESULT_OK) {
                mGoogleApiClient.connect();
            } else {
                // Bring up an error dialog to alert the user that sign-in
                // failed. The R.string.signin_failure should reference an error
                // string in your strings.xml file that tells the user they
                // could not be signed in, such as "Unable to sign in."
                BaseGameUtils.showActivityResultError(this,
                        requestCode, resultCode, R.string.signin_failure);
            }
        }
    }

    // Call when the sign-in button is clicked
    public void signInClicked(View v) {
        mSignInClicked = true;
        mGoogleApiClient.connect();
    }

    // Call when the sign-out button is clicked
    public void signOutclicked(View v) {
        mSignInClicked = false;
        Games.signOut(mGoogleApiClient);
    }

然后，在应用程序启动时弹出谷歌播放连接窗口

但它显示网络错误。虽然我有wifi连接。日志没有显示任何问题，我不知道从哪里开始寻找问题。

你能给我一些建议吗？