구글 로그인, 성취, 결제 접속

compile 'com.google.android.gms:play-services-auth:11.8.0'
compile 'com.google.android.gms:play-services-games:11.8.0'

<string name="google_app_id">your_game_app_idstring>

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

// 1.   client
GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_GAMES_SIGN_IN)
            .requestIdToken(this.getString(R.string.server_client_id))
            .requestEmail()
            .build();
m_GoogleSignInClient = GoogleSignIn.getClient(this, gso);

// 2.     
this.runOnUiThread(new Runnable() {
  @Override
  public void run() {
    Intent signInIntent = m_GoogleSignInClient.getSignInIntent();
    startActivityForResult(signInIntent, GOOGLE_LOGIN_REQUEST_ID);  // GOOGLE_LOGIN_REQUEST_ID     
  }
});

// 3.  onActivityResult     
Task task = GoogleSignIn.getSignedInAccountFromIntent(data);
    try {
        GoogleSignInAccount account = task.getResult(ApiException.class);
        Games.getGamesClient(this, account).setViewForPopups(getWindow().getDecorView());
        //        account.getIdToken()        
        // account.getDisplayName()     
    } catch (ApiException e) {
        Log.d(m_LogTag, "google signInResult:failed code=" + e.getStatusCode());
    }

//      id  google      id
Games.getAchievementsClient(this, account).unlock("your_achievement_id");

//          
Games.getAchievementsClient(this, GoogleSignIn.getLastSignedInAccount(this))
           .getAchievementsIntent()
           .addOnSuccessListener(new OnSuccessListener() {
               @Override
               public void onSuccess(Intent intent) {
                   startActivityForResult(intent, RC_ACHIEVEMENT_UI);
               }
           });

<uses-permission android:name="com.android.vending.BILLING" />

// 1.     
IabHelper mHelper;
//   key  google play consle      ->    ->   API  ，  "          "，    RSA  
static final String base64EncodedPublicKey = "your_public_key";

// 2.     IabHelper
mHelper = new IabHelper(this, base64EncodedPublicKey); 
mHelper.enableDebugLogging(true, "PayHelper");
mHelper.startSetup(new IabHelper.OnIabSetupFinishedListener() {
    public void onIabSetupFinished(IabResult result) {
        mServicSuccess = result.isSuccess();
    }
});

// 3.                
...