Full-screen interstitial ads. The ad unit ID must be set prior to calling loadAd(AdRequest).

Publishers using DoubleClick for Publishers should use PublisherInterstitialAd.

Sample code:

 public class MyActivity extends Activity {
     private InterstitialAd mInterstitialAd;
     private Button mNextLevelButton;
     private TextView mTextView;

     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);

         // Create an interstitial ad. When a natural transition in the app occurs (such as a
         // level ending in a game), show the interstitial. In this simple example, the press of a
         // button is used instead.
         //
         // If the button is clicked before the interstitial is loaded, the user should proceed to
         // the next part of the app (in this case, the next level).
         //
         // If the interstitial is finished loading, the user will view the interstitial before
         // proceeding.
         mInterstitialAd = new InterstitialAd(this);
         mInterstitialAd.setAdUnitId("myAdUnitId");

         // Create an ad request.
         AdRequest.Builder adRequestBuilder = new AdRequest.Builder();

         // Set an AdListener.
         mInterstitialAd.setAdListener(new AdListener() {
             @Override
             public void onAdLoaded() {
                 Toast.makeText(MyActivity.this,
                         "The interstitial is loaded", Toast.LENGTH_SHORT).show();
             }

             @Override
             public void onAdClosed() {
                 // Proceed to the next level.
                 goToNextLevel();
             }
         });

         // Start loading the ad now so that it is ready by the time the user is ready to go to
         // the next level.
         mInterstitialAd.loadAd(adRequestBuilder.build());

         // Create the button to go to the next level.
         mNextLevelButton = new Button(this);
         mNextLevelButton.setText("Next Level");
         mNextLevelButton.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View view) {
                 // Show the interstitial if it is ready. Otherwise, proceed to the next level
                 // without ever showing it.
                 if (mInterstitialAd.isLoaded()) {
                     mInterstitialAd.show();
                 } else {
                     // Proceed to the next level.
                     goToNextLevel();
                 }
             }
         });

         // Add the next level button to the layout.
         LinearLayout layout = new LinearLayout(this);
         layout.setOrientation(LinearLayout.VERTICAL);
         layout.addView(mNextLevelButton);

         // Create a TextView to display the current level.
         mTextView = new TextView(this);
         mTextView.setText("Level 1");
         layout.addView(mTextView);

         setContentView(layout);
     }

     public void goToNextLevel() {
         // Show the next level (and disable the next level button since there are no more levels.
         mNextLevelButton.setEnabled(false);
         mTextView.setText("Level 2");
     }
 }