FLUTTER 變現策略：讓你的應用程式
創造收入

// pubspec.yaml
dependencies:
  purchases_flutter: ^6.0.0

// Initialize RevenueCat
import 'package:purchases_flutter/purchases_flutter.dart';

class RevenueCatService {
  static const String _apiKey = 'your_revenuecat_api_key';
  
  static Future<void> initialize() async {
    await Purchases.setLogLevel(LogLevel.debug);
    
    PurchasesConfiguration configuration = PurchasesConfiguration(_apiKey);
    await Purchases.configure(configuration);
    
    // Set user ID for cross-platform tracking
    await Purchases.logIn('user_unique_id');
  }
  
  // Get available products
  static Future<List<StoreProduct>> getProducts() async {
    try {
      Offerings offerings = await Purchases.getOfferings();
      if (offerings.current != null) {
        return offerings.current!.availablePackages
            .map((package) => package.storeProduct)
            .toList();
      }
      return [];
    } catch (e) {
      print('Error fetching products: $e');
      return [];
    }
  }
  
  // Purchase a product
  static Future<bool> purchaseProduct(Package package) async {
    try {
      CustomerInfo customerInfo = await Purchases.purchasePackage(package);
      return customerInfo.entitlements.all['premium']?.isActive ?? false;
    } on PlatformException catch (e) {
      var errorCode = PurchasesErrorHelper.getErrorCode(e);
      if (errorCode == PurchasesErrorCode.purchaseCancelledError) {
        print('User cancelled purchase');
      } else if (errorCode == PurchasesErrorCode.paymentPendingError) {
        print('Payment pending');
      }
      return false;
    }
  }
  
  // Check subscription status
  static Future<bool> isPremiumUser() async {
    try {
      CustomerInfo customerInfo = await Purchases.getCustomerInfo();
      return customerInfo.entitlements.all['premium']?.isActive ?? false;
    } catch (e) {
      return false;
    }
  }
  
  // Restore purchases
  static Future<bool> restorePurchases() async {
    try {
      CustomerInfo customerInfo = await Purchases.restorePurchases();
      return customerInfo.entitlements.all['premium']?.isActive ?? false;
    } catch (e) {
      print('Error restoring purchases: $e');
      return false;
    }
  }
}

// pubspec.yaml
dependencies:
  google_mobile_ads: ^4.0.0

// AdMob service implementation
import 'package:google_mobile_ads/google_mobile_ads.dart';

class AdMobService {
  static const String bannerAdUnitId = 'ca-app-pub-your-banner-id';
  static const String interstitialAdUnitId = 'ca-app-pub-your-interstitial-id';
  static const String rewardedAdUnitId = 'ca-app-pub-your-rewarded-id';
  
  static Future<void> initialize() async {
    await MobileAds.instance.initialize();
  }
  
  // Banner Ad Widget
  static Widget createBannerAd() {
    return Container(
      alignment: Alignment.center,
      child: AdWidget(
        ad: BannerAd(
          adUnitId: bannerAdUnitId,
          size: AdSize.banner,
          request: const AdRequest(),
          listener: BannerAdListener(
            onAdLoaded: (ad) => print('Banner ad loaded'),
            onAdFailedToLoad: (ad, error) {
              print('Banner ad failed to load: $error');
              ad.dispose();
            },
          ),
        )..load(),
      ),
      width: double.infinity,
      height: 60,
    );
  }
  
  // Interstitial Ad
  static InterstitialAd? _interstitialAd;
  
  static Future<void> loadInterstitialAd() async {
    await InterstitialAd.load(
      adUnitId: interstitialAdUnitId,
      request: const AdRequest(),
      adLoadCallback: InterstitialAdLoadCallback(
        onAdLoaded: (ad) {
          _interstitialAd = ad;
          _interstitialAd!.setImmersiveMode(true);
        },
        onAdFailedToLoad: (error) {
          print('Interstitial ad failed to load: $error');
        },
      ),
    );
  }
  
  static Future<void> showInterstitialAd() async {
    if (_interstitialAd == null) {
      await loadInterstitialAd();
      return;
    }
    
    _interstitialAd!.fullScreenContentCallback = FullScreenContentCallback(
      onAdShowedFullScreenContent: (ad) {
        print('Interstitial ad showed');
      },
      onAdDismissedFullScreenContent: (ad) {
        ad.dispose();
        _interstitialAd = null;
        loadInterstitialAd(); // Preload next ad
      },
      onAdFailedToShowFullScreenContent: (ad, error) {
        ad.dispose();
        _interstitialAd = null;
      },
    );
    
    await _interstitialAd!.show();
  }
  
  // Rewarded Ad
  static RewardedAd? _rewardedAd;
  
  static Future<void> loadRewardedAd() async {
    await RewardedAd.load(
      adUnitId: rewardedAdUnitId,
      request: const AdRequest(),
      rewardedAdLoadCallback: RewardedAdLoadCallback(
        onAdLoaded: (ad) {
          _rewardedAd = ad;
        },
        onAdFailedToLoad: (error) {
          print('Rewarded ad failed to load: $error');
        },
      ),
    );
  }
  
  static Future<void> showRewardedAd({
    required Function(int amount, String type) onUserEarnedReward,
  }) async {
    if (_rewardedAd == null) {
      await loadRewardedAd();
      return;
    }
    
    _rewardedAd!.fullScreenContentCallback = FullScreenContentCallback(
      onAdDismissedFullScreenContent: (ad) {
        ad.dispose();
        _rewardedAd = null;
        loadRewardedAd(); // Preload next ad
      },
      onAdFailedToShowFullScreenContent: (ad, error) {
        ad.dispose();
        _rewardedAd = null;
      },
    );
    
    await _rewardedAd!.show(
      onUserEarnedReward: (ad, reward) {
        onUserEarnedReward(reward.amount.toInt(), reward.type);
      },
    );
  }
}

// A/B testing service for pricing
class PricingExperimentService {
  static const Map<String, Map<String, double>> pricingVariants = {
    'control': {'monthly': 9.99, 'annual': 99.99},
    'variant_a': {'monthly': 7.99, 'annual': 79.99},
    'variant_b': {'monthly': 12.99, 'annual': 119.99},
  };
  
  static String getUserVariant(String userId) {
    final hash = userId.hashCode;
    final variants = pricingVariants.keys.toList();
    return variants[hash.abs() % variants.length];
  }
  
  static Map<String, double> getPricingForUser(String userId) {
    final variant = getUserVariant(userId);
    return pricingVariants[variant]!;
  }
  
  static void trackConversion(String userId, String planType) {
    final variant = getUserVariant(userId);
    // Send to analytics
    FirebaseAnalytics.instance.logEvent(
      name: 'subscription_purchase',
      parameters: {
        'variant': variant,
        'plan_type': planType,
        'user_id': userId,
      },
    );
  }
}