【Flutter】App内购支付集成 Google和Apple支付和服务器验证全流程

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:in_app_purchase/in_app_purchase.dart';
 
class InAppPurchasePage extends StatefulWidget {
  @override
  _InAppPurchasePageState createState() => _InAppPurchasePageState();
}
 
class _InAppPurchasePageState extends State<InAppPurchasePage> {
  final InAppPurchase _inAppPurchase = InAppPurchase.instance;
  List<ProductDetails> _products = [];
  List<PurchaseDetails> _purchases = [];
  bool _isLoading = false;
 
  @override
  void initState() {
    super.initState();
    _initProducts();
  }
 
  // 初始化产品列表
  Future<void> _initProducts() async {
    const List<String> productIds = ['product1', 'product2'];
    Set<ProductDetails> products = await _inAppPurchase.bulkProductDetails(productIds);
    _products = products.map((product) => product).toList();
  }
 
  // 处理购买
  Future<void> _buyProduct(ProductDetails product) async {
    PurchaseParam purchaseParam = PurchaseParam(productDetails: product);
    if (_inAppPurchase.appStoreController != null) {
      // 对于Apple支付，需要额外的处理步骤
      final PurchaseResult result = await _inAppPurchase.buyProduct(purchaseParam);
      if(result.status == PurchaseStatus.pending) {
        // 处理等待状态，通常需要服务器验证
      }
    } else {
      // Google支付流程
      await _inAppPurchase.buyNonConsumable(purchaseParam: purchaseParam);
    }
  }
 
  // 检查购买历史
  Future<void> _fetchPurchases() async {
    _purchases = await _inAppPurchase.getPurchaseHistory();
  }
 
  // 渲染UI
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('In-App Purchase'),
      ),
      body: _isLoading ? Center(child: CircularProgressIndicator()) : ListView(
        children: <Widget>[
          ..._products.map((product) => ListTile(
            title: Text(product.title),
            subtitle: Text('\$${product.price}'),
            onTap: () => _buyProduct(product),
          )),
          ..._purchases.map((purchase) => ListTile(
            title: Text(purchase.productID),
            subtitle: Text(purchase.transactionDate.toString()),
            trailing: IconButton(
              icon: Icon(Icons.delete),
              onPressed: () async {
                // 处理验证和服务器端的退订逻辑
              },
            ),
          )),
        ],
      ),
    );
  }
}

这个代码示例提供了一个简化的Flutter页面，用于展示如何使用in_app_purchase插件来管理应用内购产