廣告預先載入 (Alpha 版)

廣告預先載入是由 SDK 管理的載入和快取程序，可省去手動載入和快取廣告的麻煩。這個程序可讓您在需要時顯示廣告，不必手動載入廣告或處理廣告載入回呼。

本指南說明如何設定預先載入廣告、檢查預先載入廣告是否可用，以及如何取得並顯示預先載入廣告。

必要條件

繼續進行本教學課程前，請先完成下列項目：

  • 安裝 Google Mobile Ads SDK (Beta 版) 0.14.0-alpha01 以上版本。
  • 完成入門指南的步驟。

開始預先載入廣告

如要開始預先載入，請呼叫 startPreload()。Google Mobile Ads SDK 會自動重試預先載入設定的失敗廣告請求。

以下範例會開始預先載入廣告：

Kotlin

private fun startPreloading(adUnitID: String) {
  val adRequest: AdRequest = AdRequest.Builder(adUnitID).build()
  val preloadConfig = PreloadConfiguration(adRequest)
  InterstitialAdPreloader.start(adUnitID, preloadConfig)
}

Java

private void startPreloading(String adUnitId) {
  AdRequest adRequest = new AdRequest.Builder(adUnitId).build();
  PreloadConfiguration preloadConfig = new PreloadConfiguration(adRequest);
  InterstitialAdPreloader.start(adUnitId, preloadConfig);
}

選用：修改預先載入廣告

如要變更預先載入的廣告，請呼叫 destroy()，然後使用修改後的設定再次呼叫 startPreload()。

選用：停止預先載入廣告

如要停止預先載入廣告，請使用預先載入 ID 呼叫 destroy()。

選用：設定緩衝區大小

緩衝區大小會控管記憶體中預先載入的廣告數量。如果應用程式顯示廣告的速度比載入新廣告快，請將緩衝區大小設為較大的值。如果擔心記憶體用量，請將緩衝區大小設為較小的值，例如 2。

Kotlin

private fun setBufferSize(adUnitID: String) {
  val adRequest: AdRequest = AdRequest.Builder(adUnitID).build()
  val preloadConfig = PreloadConfiguration(adRequest, bufferSize = 3)
  InterstitialAdPreloader.start(adUnitID, preloadConfig)
}

Java

private void setBufferSize(String adUnitId) {
  AdRequest adRequest = new AdRequest.Builder(adUnitId).build();
  PreloadConfiguration preloadConfig = new PreloadConfiguration(adRequest, 3);
  InterstitialAdPreloader.start(adUnitId, preloadConfig);
}

選用：接收預先載入通知

實作 PreloadCallback，接收廣告預先載入事件的通知。如要偵錯和記錄，這些事件會提供回應資訊物件。

Kotlin

private fun startPreloadingWithCallback(adUnitID: String) {
  val preloadCallback =
    // [Important] Don't call ad preloader start() or pollAd() within the PreloadCallback.
    object : PreloadCallback {
      override fun onAdFailedToPreload(preloadId: String, adError: LoadAdError) {
        Log.i(
          TAG,
          ("Interstitial preload ad $preloadId failed to load with error: ${adError.message}"),
        )
        // [Optional] Get the error response info for additional details.
        // val responseInfo = adError.responseInfo
      }

      override fun onAdsExhausted(preloadId: String) {
        Log.i(TAG, "Interstitial preload ad $preloadId is not available")
      }

      override fun onAdPreloaded(preloadId: String, responseInfo: ResponseInfo) {
        Log.i(TAG, "Interstitial preload ad $preloadId is available")
      }
    }
  val adRequest: AdRequest = AdRequest.Builder(adUnitID).build()
  val preloadConfig = PreloadConfiguration(adRequest)
  InterstitialAdPreloader.start(adUnitID, preloadConfig, preloadCallback)
}

Java

private void startPreloadingWithCallback(String adUnitId) {
  PreloadCallback preloadCallback =
      // [Important] Don't call ad preloader start() or pollAd() within the PreloadCallback.
      new PreloadCallback() {
        @Override
        public void onAdFailedToPreload(String preloadId, LoadAdError adError) {
          Log.e(
              TAG,
              String.format(
                  "Interstitial preload ad %s failed to load with error: %s",
                  preloadId, adError.getMessage()));
          // [Optional] Get the error response info for additional details.
          // ResponseInfo responseInfo = adError.getResponseInfo();
        }

        @Override
        public void onAdsExhausted(String preloadId) {
          Log.i(TAG, "Interstitial preload ad " + preloadId + " is not available");
        }

        @Override
        public void onAdPreloaded(String preloadId, ResponseInfo responseInfo) {
          Log.i(TAG, "Interstitial preload ad " + preloadId + " is available");
        }
      };

  AdRequest adRequest = new AdRequest.Builder(adUnitId).build();
  PreloadConfiguration preloadConfig = new PreloadConfiguration(adRequest);
  InterstitialAdPreloader.start(adUnitId, preloadConfig, preloadCallback);
}

取得並顯示預先載入廣告

呼叫 onAdsAvailable() 後，即可顯示廣告。廣告放送完畢後，系統會持續提供廣告。取得廣告後，請監聽廣告生命週期事件並顯示廣告。

以下範例顯示預先載入的廣告：

Kotlin

private fun pollAndShowAd(activity: Activity, adUnitID: String) {
  // Polling returns the next available ad and loads another ad in the background.
  val ad = InterstitialAdPreloader.pollAd(adUnitID)

  // Interact with the ad object as needed.
  ad?.apply {
    Log.d(TAG, "Interstitial ad response info: ${this.getResponseInfo()}")
    this.adEventCallback =
      object : InterstitialAdEventCallback {
        override fun onAdImpression() {
          Log.d(TAG, "Interstitial ad recorded an impression.")
        }

        override fun onAdPaid(value: AdValue) {
          Log.d(TAG, "Interstitial ad onPaidEvent: ${value.valueMicros} ${value.currencyCode}")
        }
      }

    // Show the ad.
    ad.show(activity)
  }
}

Java

private void pollAndShowAd(Activity activity, String adUnitId) {
  // Polling returns the next available ad and loads another ad in the background.
  final InterstitialAd ad = InterstitialAdPreloader.pollAd(adUnitId);

  // Interact with the ad object as needed.
  if (ad != null) {
    Log.d(TAG, "Interstitial ad response info: " + ad.getResponseInfo());
    ad.setAdEventCallback(
        new InterstitialAdEventCallback() {
          @Override
          public void onAdImpression() {
            Log.d(TAG, "Interstitial ad recorded an impression.");
          }

          @Override
          public void onAdPaid(AdValue value) {
            Log.d(
                TAG,
                "Interstitial ad onPaidEvent: "
                    + value.getValueMicros()
                    + " "
                    + value.getCurrencyCode());
          }
        });

    // Show the ad.
    ad.show(activity);
  }
}

選用：檢查預先載入廣告是否可用

如要瞭解廣告是否可用，請撥打 isAdAvailable：

Kotlin

private fun isAdAvailable(adUnitID: String): Boolean {
  return InterstitialAdPreloader.isAdAvailable(adUnitID)
}

Java

private boolean isAdAvailable(String adUnitId) {
  return InterstitialAdPreloader.isAdAvailable(adUnitId);
}