title: Error in Adding the In-app Billing Library
body: <p>I was doing this following these steps as mentioned in the <a href="https://developer.android.com/intl/zh-CN/training/in-app-billing/preparing-iab-app.html">link</a>. </p>
  
  <ol>
  <li>Copy the <code>IInAppBillingService.aidl</code> file to your Android project.</p>
  (1) If you are using Eclipse: Import the <code>IInAppBillingService.aidl</code> file into your /src    directory.</p>
  (2) If you are developing in a non-Eclipse environment: Create the following directory /src/com/android/vending/billing and copy the <code>IInAppBillingService.aidl</code> file into this directory.</p></li>
  <li>Build your application. You should see a generated file named <code>IInAppBillingService.java</code> in the <code>/gen</code> directory of your project.</li>
  <li>Add the helper classes from the <code>/util</code> directory of the <code>TrivialDrive</code> sample to your project. Remember to change the package name declarations in those files accordingly so that your project compiles correctly.</li>
  </ol>
  
  <p>But when I finished that, Eclipse gives me an error:</p>
  
  <pre><code>interface IInAppBillingService should be declared in a file called com\android\vending\billing\IInAppBillingService.aidl.
  </code></pre>
  
  <p>the <code>aidl</code> file is in the correct directory, but the  <code>IInAppBillingService.java</code> file was not generated. </p>
  
  <p>Has anybody seen that before?</p>