应用内结算 mPurchaseFinishedListener 错误

In-app billing mPurchaseFinishedListener error

我遵循了this指南,在指南的中间我遇到了这个方法:

public void buyClick(View view) {
        mHelper.launchPurchaseFlow(this, ITEM_SKU, 10001,
            mPurchaseFinishedListener, "mypurchasetoken");
    }

我需要将它复制到我的应用程序代码中,出于某种原因,mPurchaseFinishedListener(我正在使用 Android Studio)是红色的(意味着有一个错误)。

当我用鼠标悬停在 mPurchaseFinishedListener 时,Android 工作室说 "Cannot resolve simbol 'mPurchaseFinishedListener'"

现在显然我做错了什么,有人可以帮助我吗?

谢谢你

您是否在链接的教程中将 IabHelper.OnIabPurchaseFinishedListener 实现为 suggested

IabHelper.OnIabPurchaseFinishedListener mPurchaseFinishedListener 
    = new IabHelper.OnIabPurchaseFinishedListener() {
    public void onIabPurchaseFinished(IabResult result, 
                    Purchase purchase) 
    {
       if (result.isFailure()) {
          // Handle error
          return;
     }      
     else if (purchase.getSku().equals(ITEM_SKU)) {
         consumeItem();
        buyButton.setEnabled(false);
    }

   }
};