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开屏广告

本指南面向希望使用 Google 移动广告 SDK 集成开屏广告的发布商。

开屏广告是一种特殊的广告格式，适合希望通过应用加载页面创收的发布商。开屏广告在用户将您的应用切换为在前台运行时展示，用户可随时关闭。

开屏广告会自动在一个较小的区域内展示您的品牌信息，让用户知道他们是在您的应用中。以下是一个开屏广告示例：

前提条件

完成入门指南。

务必用测试广告进行测试

在构建和测试应用时，请确保使用的是测试广告，而不是实际投放的广告。否则，可能会导致您的账号被中止。

对于开屏广告，加载测试广告最简便的方法就是使用下面的测试专用广告单元 ID：

/21775744923/example/app-open

该测试广告单元 ID 已经过专门配置，可确保每个请求返回的都是测试广告。您可以在自己应用的编码、测试和调试过程中随意使用该测试广告单元 ID。只需确保您会在发布应用前用自己的广告单元 ID 替换该测试广告单元 ID 即可。

如需详细了解 Google 移动广告 SDK 的测试广告如何运作，请参阅启用测试广告。

扩展 Application 类

创建一个扩展 Application 类的新类，并添加以下代码，以便在应用启动时初始化 Google 移动广告 SDK。

Java

/** Application class that initializes, loads and show ads when activities change states. */
public class MyApplication extends Application {

  @Override
  public void onCreate() {
    super.onCreate();
    new Thread(
            () -> {
              // Initialize the Google Mobile Ads SDK on a background thread.
              MobileAds.initialize(this, initializationStatus -> {});
            })
        .start();
  }
}

Kotlin

/** Application class that initializes, loads and show ads when activities change states. */
class MyApplication : Application() {

  override fun onCreate() {
    super.onCreate()
    val backgroundScope = CoroutineScope(Dispatchers.IO)
    backgroundScope.launch {
      // Initialize the Google Mobile Ads SDK on a background thread.
      MobileAds.initialize(this@MyApplication) {}
    }
  }
}

这会初始化 SDK 并提供一个框架，供您稍后在其中注册应用前台事件。

接下来，将以下代码添加到您的 AndroidManifest.xml 中：

<!-- TODO: Update to reference your actual package name. -->
<application
    android:name="com.google.android.gms.example.appopendemo.MyApplication" ...>
...
</application>

实现实用程序组件

您的广告应该要快速展示，因此最好先加载广告，以备需要展示时使用。这样一来，用户进入您的应用后，广告便可以立即展示。

实现实用工具组件 AppOpenAdManager，以便在需要展示广告之前发出广告请求。

Java

public class MyApplication extends Application {
  // ...
  /** Inner class that loads and shows app open ads. */
  private class AppOpenAdManager {
    private static final String LOG_TAG = "AppOpenAdManager";
    private static final String AD_UNIT_ID = "/21775744923/example/app-open";

    private AppOpenAd appOpenAd = null;
    private boolean isLoadingAd = false;
    private boolean isShowingAd = false;

    /** Constructor. */
    public AppOpenAdManager() {}

    /** Request an ad. */
    private void loadAd(Context context) {
      // We will implement this later.
    }

    /** Check if ad exists and can be shown. */
    private boolean isAdAvailable() {
      return appOpenAd != null;
    }
  }
}

Kotlin

private const val String LOG_TAG = "AppOpenAdManager"
private const val String AD_UNIT_ID = "/21775744923/example/app-open"

public class MyApplication extends Application {
  // ...
  /** Inner class that loads and shows app open ads. */
  private inner class AppOpenAdManager {
    private var appOpenAd: AppOpenAd? = null
    private var isLoadingAd = false
    var isShowingAd = false

    /** Request an ad. */
    fun loadAd(context: Context) {
      // We will implement this later.
    }

    /** Check if ad exists and can be shown. */
    private fun isAdAvailable(): Boolean {
      return appOpenAd != null
    }
  }
}

现在您已拥有实用工具类，可以在 MyApplication 类中将其实例化：

Java

public class MyApplication extends Application {

  private AppOpenAdManager appOpenAdManager;

  @Override
  public void onCreate() {
    super.onCreate();
    new Thread(
            () -> {
              // Initialize the Google Mobile Ads SDK on a background thread.
              MobileAds.initialize(this, initializationStatus -> {});
            })
        .start();
    appOpenAdManager = new AppOpenAdManager(this);
  }
}

Kotlin

class MyApplication : Application() {

  private lateinit var appOpenAdManager: AppOpenAdManager

  override fun onCreate() {
    super.onCreate()
    val backgroundScope = CoroutineScope(Dispatchers.IO)
    backgroundScope.launch {
      // Initialize the Google Mobile Ads SDK on a background thread.
      MobileAds.initialize(this@MyApplication) {}
    }
    appOpenAdManager = AppOpenAdManager()
  }
}

加载广告

下一步是填充 loadAd() 方法并处理广告加载回调。

Java

private class AppOpenAdManager {
  // ...
  /** Request an ad. */
  public void loadAd(Context context) {
    // Do not load ad if there is an unused ad or one is already loading.
    if (isLoadingAd || isAdAvailable()) {
      return;
    }

    isLoadingAd = true;
    AdRequest request = new AdRequest.Builder().build();
    AppOpenAd.load(
        context, AD_UNIT_ID, request,
        AppOpenAd.APP_OPEN_AD_ORIENTATION_PORTRAIT,
        new AppOpenAdLoadCallback() {
          @Override
          public void onAdLoaded(AppOpenAd ad) {
            // Called when an app open ad has loaded.
            Log.d(LOG_TAG, "Ad was loaded.");
            appOpenAd = ad;
            isLoadingAd = false;
            loadTime = (new Date()).getTime();
          }

          @Override
          public void onAdFailedToLoad(LoadAdError loadAdError) {
            // Called when an app open ad has failed to load.
            Log.d(LOG_TAG, loadAdError.getMessage());
            isLoadingAd = false;
          }
        });
  }
  // ...
}

Kotlin

private inner class AppOpenAdManager {
  // ...
  /** Request an ad. */
  fun loadAd(context: Context) {
    // Do not load ad if there is an unused ad or one is already loading.
    if (isLoadingAd || isAdAvailable()) {
      return
    }

    isLoadingAd = true
    val request = AdRequest.Builder().build()
    AppOpenAd.load(
        context, AD_UNIT_ID, request,
        AppOpenAd.APP_OPEN_AD_ORIENTATION_PORTRAIT,
        object : AppOpenAdLoadCallback() {

          override fun onAdLoaded(ad: AppOpenAd) {
            // Called when an app open ad has loaded.
            Log.d(LOG_TAG, "Ad was loaded.")
            appOpenAd = ad
            isLoadingAd = false
            loadTime = Date().time
          }

          override fun onAdFailedToLoad(loadAdError: LoadAdError) {
            // Called when an app open ad has failed to load.
            Log.d(LOG_TAG, loadAdError.message)
            isLoadingAd = false;
          }
        })
  }
  // ...
}

展示广告并处理全屏回调事件

最常见的开屏广告实现方式是尝试在应用启动时附近展示开屏广告，如果广告尚未准备就绪，则启动应用内容，并预加载另一个广告以便在下次应用打开时展示。如需查看实现示例，请参阅开屏广告指南。

以下代码演示了如何展示广告以及随后重新加载广告：

Java

public class MyApplication extends Application {
  // ...
  /** Interface definition for a callback to be invoked when an app open ad is complete. */
  public interface OnShowAdCompleteListener {
    void onShowAdComplete();
  }

  private class AppOpenAdManager {
    // ...

    /** Shows the ad if one isn't already showing. */
    public void showAdIfAvailable(
        @NonNull final Activity activity,
        @NonNull OnShowAdCompleteListener onShowAdCompleteListener){
      // If the app open ad is already showing, do not show the ad again.
      if (isShowingAd) {
        Log.d(LOG_TAG, "The app open ad is already showing.");
        return;
      }

      // If the app open ad is not available yet, invoke the callback then load the ad.
      if (!isAdAvailable()) {
        Log.d(LOG_TAG, "The app open ad is not ready yet.");
        onShowAdCompleteListener.onShowAdComplete();
        loadAd(activity);
        return;
      }

      appOpenAd.setFullScreenContentCallback(
          new FullScreenContentCallback() {

            @Override
            public void onAdDismissedFullScreenContent() {
              // Called when fullscreen content is dismissed.
              // Set the reference to null so isAdAvailable() returns false.
              Log.d(LOG_TAG, "Ad dismissed fullscreen content.");
              appOpenAd = null;
              isShowingAd = false;

              onShowAdCompleteListener.onShowAdComplete();
              loadAd(activity);
            }

            @Override
            public void onAdFailedToShowFullScreenContent(AdError adError) {
              // Called when fullscreen content failed to show.
              // Set the reference to null so isAdAvailable() returns false.
              Log.d(LOG_TAG, adError.getMessage());
              appOpenAd = null;
              isShowingAd = false;

              onShowAdCompleteListener.onShowAdComplete();
              loadAd(activity);
            }

            @Override
            public void onAdShowedFullScreenContent() {
              // Called when fullscreen content is shown.
              Log.d(LOG_TAG, "Ad showed fullscreen content.");
            }
          });
      isShowingAd = true;
      appOpenAd.show(activity);
    }
    // ...
  }
}

Kotlin

class MyApplication : Application() {
  // ...
  /** Interface definition for a callback to be invoked when an app open ad is complete. */
  interface OnShowAdCompleteListener {
    fun onShowAdComplete()
  }

  private inner class AppOpenAdManager {
    // ...

    /** Shows the ad if one isn't already showing. */
    fun showAdIfAvailable(
        activity: Activity,
        onShowAdCompleteListener: OnShowAdCompleteListener) {
      // If the app open ad is already showing, do not show the ad again.
      if (isShowingAd) {
        Log.d(LOG_TAG, "The app open ad is already showing.")
        return
      }

      // If the app open ad is not available yet, invoke the callback then load the ad.
      if (!isAdAvailable()) {
        Log.d(LOG_TAG, "The app open ad is not ready yet.")
        onShowAdCompleteListener.onShowAdComplete()
        loadAd(activity)
        return
      }

      appOpenAd?.setFullScreenContentCallback(
          object : FullScreenContentCallback() {

            override fun onAdDismissedFullScreenContent() {
              // Called when full screen content is dismissed.
              // Set the reference to null so isAdAvailable() returns false.
              Log.d(LOG_TAG, "Ad dismissed fullscreen content.")
              appOpenAd = null
              isShowingAd = false

              onShowAdCompleteListener.onShowAdComplete()
              loadAd(activity)
            }

            override fun onAdFailedToShowFullScreenContent(adError: AdError) {
              // Called when fullscreen content failed to show.
              // Set the reference to null so isAdAvailable() returns false.
              Log.d(LOG_TAG, adError.message)
              appOpenAd = null
              isShowingAd = false

              onShowAdCompleteListener.onShowAdComplete()
              loadAd(activity)
            }

            override fun onAdShowedFullScreenContent() {
              // Called when fullscreen content is shown.
              Log.d(LOG_TAG, "Ad showed fullscreen content.")
            }
          })
      isShowingAd = true
      appOpenAd?.show(activity)
    }
    // ...
  }
}

FullScreenContentCallback 会处理各种事件，例如广告展示、广告无法展示或者用户关闭广告。

考虑广告有效期

为确保您不会展示过期的广告，请在 AppOpenAdManager 中添加一个方法，用于检查广告引用加载后经过了多长时间。然后，使用该方法检查广告是否仍然有效。

Java

private class AppOpenAdManager {
  // ...
  /** Keep track of the time an app open ad is loaded to ensure you don't show an expired ad. */
  private long loadTime = 0;

  // ...

  /** Utility method to check if ad was loaded more than n hours ago. */
  private boolean wasLoadTimeLessThanNHoursAgo(long numHours) {
    long dateDifference = (new Date()).getTime() - this.loadTime;
    long numMilliSecondsPerHour = 3600000;
    return (dateDifference < (numMilliSecondsPerHour * numHours));
  }

  /** Check if ad exists and can be shown. */
  public boolean isAdAvailable() {
    return appOpenAd != null && wasLoadTimeLessThanNHoursAgo(4);
  }
}

Kotlin

private inner class AppOpenAdManager {
  // ...
  /** Keep track of the time an app open ad is loaded to ensure you don't show an expired ad. */
  private var loadTime: Long = 0;

  // ...

  /** Utility method to check if ad was loaded more than n hours ago. */
  private fun wasLoadTimeLessThanNHoursAgo(numHours: Long): Boolean {
    val dateDifference: Long = Date().time - loadTime
    val numMilliSecondsPerHour: Long = 3600000
    return dateDifference < numMilliSecondsPerHour * numHours
  }

  /** Check if ad exists and can be shown. */
  private fun isAdAvailable(): Boolean {
    return appOpenAd != null && wasLoadTimeLessThanNHoursAgo(4)
  }
}

跟踪当前 activity

您需要 Activity 上下文才能展示广告。如需跟踪用户使用的最新 activity，请注册并实现 Application.ActivityLifecycleCallbacks。

Java

public class MyApplication extends Application implements ActivityLifecycleCallbacks {

  private Activity currentActivity;

  @Override
  public void onCreate() {
    super.onCreate();
    this.registerActivityLifecycleCallbacks(this);
    // ...
  }

  /** ActivityLifecycleCallback methods. */
  @Override
  public void onActivityCreated(Activity activity, Bundle savedInstanceState) {}

  @Override
  public void onActivityStarted(Activity activity) {
    currentActivity = activity
  }

  @Override
  public void onActivityResumed(Activity activity) {}

  @Override
  public void onActivityStopped(Activity activity) {}

  @Override
  public void onActivityPaused(Activity activity) {}

  @Override
  public void onActivitySaveInstanceState(Activity activity, Bundle bundle) {}

  @Override
  public void onActivityDestroyed(Activity activity) {}
}

Kotlin

class MyApplication : Application(), Application.ActivityLifecycleCallbacks {

  private var currentActivity: Activity? = null

  override fun onCreate() {
    super.onCreate()
    registerActivityLifecycleCallbacks(this)
    // ...
  }

  /** ActivityLifecycleCallback methods. */
  override fun onActivityCreated(activity: Activity, savedInstanceState: Bundle?) {}

  override fun onActivityStarted(activity: Activity) {
    currentActivity = activity
  }

  override fun onActivityResumed(activity: Activity) {}

  override fun onActivityPaused(activity: Activity) {}

  override fun onActivityStopped(activity: Activity) {}

  override fun onActivitySaveInstanceState(activity: Activity, outState: Bundle) {}

  override fun onActivityDestroyed(activity: Activity) {}
}

registerActivityLifecycleCallbacks 可用于监听所有 Activity 事件。通过监听 activity 启动和销毁的时间，您可以跟踪对当前 Activity 的引用，然后根据该 activity 展示您的开屏广告。

监听应用前台事件

将库添加到 gradle 文件中

如需接收应用前台事件的通知，您需要注册 DefaultLifecycleObserver。将其依赖项添加到应用级 build 文件中：

Kotlin

  dependencies {
    implementation("com.google.android.gms:play-services-ads:23.5.0")
    implementation("androidx.lifecycle:lifecycle-process:2.8.3")
  }

Groovy

  dependencies {
    implementation 'com.google.android.gms:play-services-ads:23.5.0'
    implementation 'androidx.lifecycle:lifecycle-process:2.8.3'
  }

实现生命周期观察器接口

您可以通过实现 DefaultLifecycleObserver 接口来监听前台事件。

实现 onStart 事件以展示开屏广告。

Java

public class MyApplication extends Application
    implements ActivityLifecycleCallbacks, LifecycleObserver {
  // ...
  @Override
  public void onCreate() {
    super.onCreate();
    this.registerActivityLifecycleCallbacks(this);
    new Thread(
            () -> {
              // Initialize the Google Mobile Ads SDK on a background thread.
              MobileAds.initialize(this, initializationStatus -> {});
            })
        .start();
    ProcessLifecycleOwner.get().getLifecycle().addObserver(this);
    appOpenAdManager = new AppOpenAdManager();
  }

  /** LifecycleObserver method that shows the app open ad when the app moves to foreground. */
  @OnLifecycleEvent(Event.ON_START)
  protected void onMoveToForeground() {
    // Show the ad (if available) when the app moves to foreground.
    appOpenAdManager.showAdIfAvailable(currentActivity);
  }

  /** Show the ad if one isn't already showing. */
  private void showAdIfAvailable(@NonNull final Activity activity) {
      showAdIfAvailable(
          activity,
          new OnShowAdCompleteListener() {
            @Override
            public void onShowAdComplete() {
              // Empty because the user will go back to the activity that shows the ad.
            }
          });
  }
}

Kotlin

class MyApplication : Application(),
    Application.ActivityLifecycleCallbacks, LifecycleObserver {
  // ...
  override fun onCreate() {
    super.onCreate()
    registerActivityLifecycleCallbacks(this)
    val backgroundScope = CoroutineScope(Dispatchers.IO)
    backgroundScope.launch {
      // Initialize the Google Mobile Ads SDK on a background thread.
      MobileAds.initialize(this@MyApplication) {}
    }
    ProcessLifecycleOwner.get().lifecycle.addObserver(this)
    appOpenAdManager = AppOpenAdManager()
  }

  /** LifecycleObserver method that shows the app open ad when the app moves to foreground. */
  @OnLifecycleEvent(Lifecycle.Event.ON_START)
  fun onMoveToForeground() {
    // Show the ad (if available) when the app moves to foreground.
    currentActivity?.let {
      appOpenAdManager.showAdIfAvailable(it)
    }
  }

  /** Show the ad if one isn't already showing. */
  fun showAdIfAvailable(activity: Activity) {
    showAdIfAvailable(
        activity,
        object : OnShowAdCompleteListener {
          override fun onShowAdComplete() {
            // Empty because the user will go back to the activity that shows the ad.
          }
        })
  }
}

冷启动和加载屏幕

到现在为止，本文档都假定您仅在以下情况下展示开屏广告：用户将在内存中挂起的应用切换为在前台运行。用户启动您的应用，但该应用之前未在内存中挂起，这种情况就称为“冷启动”。

例如，用户首次打开您的应用便属于冷启动。对于冷启动，您没有之前已加载的开屏广告可供立即展示。请求广告和收到相应广告之间的延迟会导致出现以下情况：用户能够暂时使用您的应用，然后突然看到一条无关广告。应避免出现这种情况，因为这会导致用户体验不佳。

在冷启动时使用开屏广告的首选方法是，使用加载屏幕来加载游戏或应用素材资源，并且仅在加载屏幕展示广告。如果您的应用已加载完毕，并且用户已经看到应用的主要内容，则不要展示广告。

最佳做法

借助开屏广告，您可以在用户首次启动应用和切换应用期间通过应用的加载屏幕变现，不过，还请务必考虑一些最佳做法，以便保持良好的应用使用体验。最佳做法如下所示：

在用户使用几次您的应用后展示第一个开屏广告。
利用用户等待您应用加载的那段时间，展示开屏广告。
如果有加载屏幕位于开屏广告之下，并且加载屏幕在用户关闭广告之前已加载完毕，您可能需要通过 onAdDismissedFullScreenContent() 方法关闭加载屏幕。

GitHub 上的示例

开屏广告示例： Java | Kotlin

后续步骤

不妨探索以下主题：