Code example for FragmentActivity

Methods: onActivityResult

        billingHelper.launchPurchaseFlow(this, sku, 123, this);
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        billingHelper.handleActivityResult(requestCode, resultCode, data);
     * Security Recommendation: When you receive the purchase response from 
     * Google Play, make sure to check the returned data signature, the orderId, 
     * and the developerPayload string in the Purchase object to make sure that 
     * you are getting the expected values. You should verify that the orderId 
     * is a unique value that you have not previously processed, and the 
     * developerPayload string matches the token that you sent previously with 
     * the purchase request. As a further security precaution, you should 
     * perform the verification on your own secure server.