The next step is to have the application code listen for these app events. Here are the iOS and Android versions of this method, respectively:

// iOS
- (void)adView:(DFPBannerView *)banner
    didReceiveAppEvent:(NSString *)name
    withInfo:(NSString *)info {
  NSLog(@"Received app event (%@, %@)", name, info);
  // Checking for a "color" event name with information being a color.
  if ([name isEqualToString:@"color"]) {
    if ([info isEqualToString:@"red"]) {
      self.view.backgroundColor = [UIColor redColor];
    } else if ([info isEqualToString:@"green"]) {
      self.view.backgroundColor = [UIColor greenColor];
    }
  }
}

// Android
@Override
public void onAppEvent(Ad ad, String name, String info) {
  String message = String.format("Received app event (%s, %s)", name, info);
  Log.d(LOG_TAG, message);
  if ("color".equals(name)) {
    LinearLayout layout = (LinearLayout) findViewById(R.id.mainLayout);
    if ("red".equals(info)) {
      layout.setBackgroundColor(Color.RED);
    } else if ("green".equals(info)) {
      layout.setBackgroundColor(Color.GREEN);
    }
  }
}

Remember to register this callback on the banner view:

// iOS
[bannerView_ setAppEventDelegate:self];

// Android
adView.setAppEventListener(this);

That’s it! If you load this ad into your banner view, your application will change its background color to red when the ad is loaded, and green when the ad is clicked. This example can be extended to change the implementation of the app event listener or to fire app events at any point during the creative’s lifecycle.

Let us know on the forum if you have any questions about app events specifically or the Google AdMob SDK in general. You can also follow us on our plus page for AdMob-related updates.

Edit: Fixed plus page link.

 - Eric Leichtenschlag, AdMob Team