问题
I am going to add in-app-purchase functionality to my flutter app, but could not find any relevant information or sample app about in-app-purchases, can anyone share any links or example apps that contain in-app-purchase functionality? Thank you
回答1:
Have a look at this package
https://pub.dev/packages/in_app_purchase
dependencies:
in_app_purchase: ^0.3.4+8
Example code:
import 'dart:async';
import 'dart:io';
import 'package:flutter/material.dart';
import 'package:in_app_purchase/in_app_purchase.dart';
import 'consumable_store.dart';
void main() {
// For play billing library 2.0 on Android, it is mandatory to call
// [enablePendingPurchases](https://developer.android.com/reference/com/android/billingclient/api/BillingClient.Builder.html#enablependingpurchases)
// as part of initializing the app.
InAppPurchaseConnection.enablePendingPurchases();
runApp(MyApp());
}
const bool kAutoConsume = true;
const String _kConsumableId = 'consumable';
const List<String> _kProductIds = <String>[
_kConsumableId,
'upgrade',
'subscription'
];
class MyApp extends StatefulWidget {
@override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
final InAppPurchaseConnection _connection = InAppPurchaseConnection.instance;
StreamSubscription<List<PurchaseDetails>> _subscription;
List<String> _notFoundIds = [];
List<ProductDetails> _products = [];
List<PurchaseDetails> _purchases = [];
List<String> _consumables = [];
bool _isAvailable = false;
bool _purchasePending = false;
bool _loading = true;
String _queryProductError;
@override
void initState() {
Stream purchaseUpdated =
InAppPurchaseConnection.instance.purchaseUpdatedStream;
_subscription = purchaseUpdated.listen((purchaseDetailsList) {
_listenToPurchaseUpdated(purchaseDetailsList);
}, onDone: () {
_subscription.cancel();
}, onError: (error) {
// handle error here.
});
initStoreInfo();
super.initState();
}
Future<void> initStoreInfo() async {
final bool isAvailable = await _connection.isAvailable();
if (!isAvailable) {
setState(() {
_isAvailable = isAvailable;
_products = [];
_purchases = [];
_notFoundIds = [];
_consumables = [];
_purchasePending = false;
_loading = false;
});
return;
}
ProductDetailsResponse productDetailResponse =
await _connection.queryProductDetails(_kProductIds.toSet());
if (productDetailResponse.error != null) {
setState(() {
_queryProductError = productDetailResponse.error.message;
_isAvailable = isAvailable;
_products = productDetailResponse.productDetails;
_purchases = [];
_notFoundIds = productDetailResponse.notFoundIDs;
_consumables = [];
_purchasePending = false;
_loading = false;
});
return;
}
if (productDetailResponse.productDetails.isEmpty) {
setState(() {
_queryProductError = null;
_isAvailable = isAvailable;
_products = productDetailResponse.productDetails;
_purchases = [];
_notFoundIds = productDetailResponse.notFoundIDs;
_consumables = [];
_purchasePending = false;
_loading = false;
});
return;
}
final QueryPurchaseDetailsResponse purchaseResponse =
await _connection.queryPastPurchases();
if (purchaseResponse.error != null) {
// handle query past purchase error..
}
final List<PurchaseDetails> verifiedPurchases = [];
for (PurchaseDetails purchase in purchaseResponse.pastPurchases) {
if (await _verifyPurchase(purchase)) {
verifiedPurchases.add(purchase);
}
}
List<String> consumables = await ConsumableStore.load();
setState(() {
_isAvailable = isAvailable;
_products = productDetailResponse.productDetails;
_purchases = verifiedPurchases;
_notFoundIds = productDetailResponse.notFoundIDs;
_consumables = consumables;
_purchasePending = false;
_loading = false;
});
}
@override
void dispose() {
_subscription.cancel();
super.dispose();
}
@override
Widget build(BuildContext context) {
List<Widget> stack = [];
if (_queryProductError == null) {
stack.add(
ListView(
children: [
_buildConnectionCheckTile(),
_buildProductList(),
_buildConsumableBox(),
],
),
);
} else {
stack.add(Center(
child: Text(_queryProductError),
));
}
if (_purchasePending) {
stack.add(
Stack(
children: [
Opacity(
opacity: 0.3,
child: const ModalBarrier(dismissible: false, color: Colors.grey),
),
Center(
child: CircularProgressIndicator(),
),
],
),
);
}
return MaterialApp(
home: Scaffold(
appBar: AppBar(
title: const Text('IAP Example'),
),
body: Stack(
children: stack,
),
),
);
}
Card _buildConnectionCheckTile() {
if (_loading) {
return Card(child: ListTile(title: const Text('Trying to connect...')));
}
final Widget storeHeader = ListTile(
leading: Icon(_isAvailable ? Icons.check : Icons.block,
color: _isAvailable ? Colors.green : ThemeData.light().errorColor),
title: Text(
'The store is ' + (_isAvailable ? 'available' : 'unavailable') + '.'),
);
final List<Widget> children = <Widget>[storeHeader];
if (!_isAvailable) {
children.addAll([
Divider(),
ListTile(
title: Text('Not connected',
style: TextStyle(color: ThemeData.light().errorColor)),
subtitle: const Text(
'Unable to connect to the payments processor. Has this app been configured correctly? See the example README for instructions.'),
),
]);
}
return Card(child: Column(children: children));
}
Card _buildProductList() {
if (_loading) {
return Card(
child: (ListTile(
leading: CircularProgressIndicator(),
title: Text('Fetching products...'))));
}
if (!_isAvailable) {
return Card();
}
final ListTile productHeader = ListTile(title: Text('Products for Sale'));
List<ListTile> productList = <ListTile>[];
if (_notFoundIds.isNotEmpty) {
productList.add(ListTile(
title: Text('[${_notFoundIds.join(", ")}] not found',
style: TextStyle(color: ThemeData.light().errorColor)),
subtitle: Text(
'This app needs special configuration to run. Please see example/README.md for instructions.')));
}
// This loading previous purchases code is just a demo. Please do not use this as it is.
// In your app you should always verify the purchase data using the `verificationData` inside the [PurchaseDetails] object before trusting it.
// We recommend that you use your own server to verity the purchase data.
Map<String, PurchaseDetails> purchases =
Map.fromEntries(_purchases.map((PurchaseDetails purchase) {
if (purchase.pendingCompletePurchase) {
InAppPurchaseConnection.instance.completePurchase(purchase);
}
return MapEntry<String, PurchaseDetails>(purchase.productID, purchase);
}));
productList.addAll(_products.map(
(ProductDetails productDetails) {
PurchaseDetails previousPurchase = purchases[productDetails.id];
return ListTile(
title: Text(
productDetails.title,
),
subtitle: Text(
productDetails.description,
),
trailing: previousPurchase != null
? Icon(Icons.check)
: FlatButton(
child: Text(productDetails.price),
color: Colors.green[800],
textColor: Colors.white,
onPressed: () {
PurchaseParam purchaseParam = PurchaseParam(
productDetails: productDetails,
applicationUserName: null,
sandboxTesting: true);
if (productDetails.id == _kConsumableId) {
_connection.buyConsumable(
purchaseParam: purchaseParam,
autoConsume: kAutoConsume || Platform.isIOS);
} else {
_connection.buyNonConsumable(
purchaseParam: purchaseParam);
}
},
));
},
));
return Card(
child:
Column(children: <Widget>[productHeader, Divider()] + productList));
}
Card _buildConsumableBox() {
if (_loading) {
return Card(
child: (ListTile(
leading: CircularProgressIndicator(),
title: Text('Fetching consumables...'))));
}
if (!_isAvailable || _notFoundIds.contains(_kConsumableId)) {
return Card();
}
final ListTile consumableHeader =
ListTile(title: Text('Purchased consumables'));
final List<Widget> tokens = _consumables.map((String id) {
return GridTile(
child: IconButton(
icon: Icon(
Icons.stars,
size: 42.0,
color: Colors.orange,
),
splashColor: Colors.yellowAccent,
onPressed: () => consume(id),
),
);
}).toList();
return Card(
child: Column(children: <Widget>[
consumableHeader,
Divider(),
GridView.count(
crossAxisCount: 5,
children: tokens,
shrinkWrap: true,
padding: EdgeInsets.all(16.0),
)
]));
}
Future<void> consume(String id) async {
await ConsumableStore.consume(id);
final List<String> consumables = await ConsumableStore.load();
setState(() {
_consumables = consumables;
});
}
void showPendingUI() {
setState(() {
_purchasePending = true;
});
}
void deliverProduct(PurchaseDetails purchaseDetails) async {
// IMPORTANT!! Always verify a purchase purchase details before delivering the product.
if (purchaseDetails.productID == _kConsumableId) {
await ConsumableStore.save(purchaseDetails.purchaseID);
List<String> consumables = await ConsumableStore.load();
setState(() {
_purchasePending = false;
_consumables = consumables;
});
} else {
setState(() {
_purchases.add(purchaseDetails);
_purchasePending = false;
});
}
}
void handleError(IAPError error) {
setState(() {
_purchasePending = false;
});
}
Future<bool> _verifyPurchase(PurchaseDetails purchaseDetails) {
// IMPORTANT!! Always verify a purchase before delivering the product.
// For the purpose of an example, we directly return true.
return Future<bool>.value(true);
}
void _handleInvalidPurchase(PurchaseDetails purchaseDetails) {
// handle invalid purchase here if _verifyPurchase` failed.
}
void _listenToPurchaseUpdated(List<PurchaseDetails> purchaseDetailsList) {
purchaseDetailsList.forEach((PurchaseDetails purchaseDetails) async {
if (purchaseDetails.status == PurchaseStatus.pending) {
showPendingUI();
} else {
if (purchaseDetails.status == PurchaseStatus.error) {
handleError(purchaseDetails.error);
} else if (purchaseDetails.status == PurchaseStatus.purchased) {
bool valid = await _verifyPurchase(purchaseDetails);
if (valid) {
deliverProduct(purchaseDetails);
} else {
_handleInvalidPurchase(purchaseDetails);
return;
}
}
if (Platform.isAndroid) {
if (!kAutoConsume && purchaseDetails.productID == _kConsumableId) {
await InAppPurchaseConnection.instance
.consumePurchase(purchaseDetails);
}
}
if (purchaseDetails.pendingCompletePurchase) {
await InAppPurchaseConnection.instance
.completePurchase(purchaseDetails);
}
}
});
}
}
来源：https://stackoverflow.com/questions/63985943/how-can-i-dd-in-app-purchase-functionality-to-my-flutter-app