Banner ads

Banner ads are rectangular image or text ads that occupy a spot on screen. They stay on screen while users are interacting with the app, and can refresh automatically after a certain period of time. If you're new to mobile advertising, they're a great place to start. Case study.

This guide shows you how to integrate banner ads from AdMob into a Unity app. In addition to code snippets and instructions, it also includes information about sizing banners properly and links to additional resources.

Prerequisites

• Complete the Get started guide.

Always test with test ads

The sample code below contains an ad unit ID which you can use to request test ads. It's been specially configured to return test ads rather than production ads for every request, making it safe to use.

However, once you register an app in the AdMob UI and create your own ad unit IDs for use in your app, you'll need to explicitly configure your device as a test device during development.

ca-app-pub-3940256099942544/6300978111

ca-app-pub-3940256099942544/2934735716

Initialize the Mobile Ads SDK

Before loading ads, have your app initialize the Mobile Ads SDK by calling MobileAds.Initialize(). This needs to be done only once, ideally at app launch.

using GoogleMobileAds;
using GoogleMobileAds.Api;

public class GoogleMobileAdsDemoScript : MonoBehaviour
{
    public void Start()
    {
        // Initialize the Google Mobile Ads SDK.
        MobileAds.Initialize((InitializationStatus initStatus) =>
        {
            // This callback is called once the MobileAds SDK is initialized.
        });
    }
}

If you're using mediation, wait until the callback occurs before loading ads as this will ensure that all mediation adapters are initialized.

BannerView example

The sample code below details how to use the banner view. In the example, you create an instance of a banner view, use an AdRequest to load an ad into the banner view, and then extend functionality by handling life cycle events.

Create a banner view

The first step in using a banner view is to create an instance of a banner view in a C# script attached to a GameObject.

  // These ad units are configured to always serve test ads.
#if UNITY_ANDROID
  private string _adUnitId = "ca-app-pub-3940256099942544/6300978111";
#elif UNITY_IPHONE
  private string _adUnitId = "ca-app-pub-3940256099942544/2934735716";
#else
  private string _adUnitId = "unused";
#endif

  BannerView _bannerView;

  /// <summary>
  /// Creates a 320x50 banner at top of the screen.
  /// </summary>
  public void CreateBannerView()
  {
      Debug.Log("Creating banner view");

      // If we already have a banner, destroy the old one.
      if (_bannerView != null)
      {
          DestroyAd();
      }

      // Create a 320x50 banner at top of the screen
      _bannerView = new BannerView(_adUnitId, AdSize.Banner, AdPosition.Top);
  }

The constructor for a BannerView has the following parameters:

• adUnitId: The AdMob ad unit ID from which the BannerView should load ads.
• AdSize: The AdMob ad size you'd like to use (consult Banner sizes for details).
• AdPosition: The position where the banner ad should be placed. The AdPosition enum lists the valid ad position values.

Note how different ad units are used, depending on the platform. You need to use an iOS ad unit for making ad requests on iOS and an Android ad unit for making requests on Android.

(Optional) Create a banner view with a custom position

For greater control over where a BannerView is placed on screen than what's offered by AdPosition values, use the BannerViewconstructor that has x- and y-coordinates as parameters:

// Create a 320x50 banner ad at coordinate (0,50) on screen.
_bannerView = new BannerView(_adUnitId, AdSize.Banner, 0, 50);

The top-left corner of the BannerView is positioned at the x and y values passed to the constructor, where the origin is the top-left of the screen.

(Optional) Create a banner view with a custom size

In addition to using an AdSize constant, you can also specify a custom size for your ad:

// Use the AdSize argument to set a custom size for the ad.
AdSize adSize = new AdSize(250, 250);
_bannerView = new BannerView(_adUnitId, adSize, AdPosition.Bottom);

Load a banner ad

The second step in using the banner view is to create an AdRequest and pass it to the LoadAd() method.

/// <summary>
/// Creates the banner view and loads a banner ad.
/// </summary>
public void LoadAd()
{
    // create an instance of a banner view first.
    if(_bannerView == null)
    {
        CreateBannerView();
    }
    // create our request used to load the ad.
    var adRequest = new AdRequest();
    adRequest.Keywords.Add("unity-admob-sample");

    // send the request to load the ad.
    Debug.Log("Loading banner ad.");
    _bannerView.LoadAd(adRequest);
}

Listen to banner view events

To customize the behavior of your ad, you can hook into a number of events in the ad's lifecycle: loading, opening, closing, and so on. To listen for these events, register a delegate:

/// <summary>
/// listen to events the banner may raise.
/// </summary>
private void ListenToAdEvents()
{
    // Raised when an ad is loaded into the banner view.
    _bannerView.OnBannerAdLoaded += () =>
    {
        Debug.Log("Banner view loaded an ad with response : "
            + _bannerView.GetResponseInfo());
    };
    // Raised when an ad fails to load into the banner view.
    _bannerView.OnBannerAdLoadFailed += (LoadAdError error) =>
    {
        Debug.LogError("Banner view failed to load an ad with error : "
            + error);
    };
    // Raised when the ad is estimated to have earned money.
    _bannerView.OnAdPaid += (AdValue adValue) =>
    {
        Debug.Log(String.Format("Banner view paid {0} {1}.",
            adValue.Value,
            adValue.CurrencyCode));
    };
    // Raised when an impression is recorded for an ad.
    _bannerView.OnAdImpressionRecorded += () =>
    {
        Debug.Log("Banner view recorded an impression.");
    };
    // Raised when a click is recorded for an ad.
    _bannerView.OnAdClicked += () =>
    {
        Debug.Log("Banner view was clicked.");
    };
    // Raised when an ad opened full screen content.
    _bannerView.OnAdFullScreenContentOpened += () =>
    {
        Debug.Log("Banner view full screen content opened.");
    };
    // Raised when the ad closed full screen content.
    _bannerView.OnAdFullScreenContentClosed += () =>
    {
        Debug.Log("Banner view full screen content closed.");
    };
}

Destroy the banner view

When finished using the banner view, be sure to call Destroy() to free up resources.

/// <summary>
/// Destroys the ad.
/// </summary>
public void DestroyAd()
{
    if (_bannerView != null)
    {
        Debug.Log("Destroying banner ad.");
        _bannerView.Destroy();
        _bannerView = null;
    }
}

That's it! Your app is now ready to display banner ads from AdMob.

Banner sizes

The table below lists the standard banner sizes.

Additional resources

Samples

• HelloWorld example: A minimal implementation of all ad formats.

Success stories

• Sample use case