插页式广告仅展示一次 - Flutter/Dart

Question

I'm trying to show interstitial ad on every 3rd click (basically after certain number of clicks) On first 3rd click, it shows interstitial ad perfectly but after that it throws the following error

ad has not been loaded or has already been disposed.

  bool _isLoaded = false;
  InterstitialAd? interstitialAd;
  int counter = 0;

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addObserver(this);
    showInterstitialAd();
  }

  void showInterstitialAd(){
    InterstitialAd.load(
        adUnitId: "ad_id",
        request: const AdRequest(),
        adLoadCallback: InterstitialAdLoadCallback(
            onAdLoaded: (ad) {
              _isLoaded = true;
              interstitialAd=ad;

              interstitialAd!.fullScreenContentCallback = FullScreenContentCallback(
                  onAdDismissedFullScreenContent: (InterstitialAd ad){
                    print('ad dismissed');
                    interstitialAd!.dispose();
                  },
                  onAdFailedToShowFullScreenContent: (InterstitialAd ad, adError){
                    print('ad failed');
                    interstitialAd!.dispose();
                  }
              );
            },
            onAdFailedToLoad: (error) {
              interstitialAd!.dispose();
            }
        ));
  }


// show ad when counter is equal to 3
void onTap (){
           if(_isLoaded && counter == 3){
                interstitialAd!.show();
                counter = 0;
           } else {
                counter ++;
           }
       }

Answer 1

Please rename your showInterstitialAd to loadInterstitialAd (because method only load and prepare ads) and call it after counter = 0;

Should look like this:

if(_isLoaded && counter == 3){
      interstitialAd!.show();
      counter = 0;
      loadInterstitialAd();
    } else {
        counter ++;
    }