Flutter统一支付接口插件get_upi的使用

当然，以下是一个关于如何在Flutter项目中使用get_upi插件来实现统一支付接口（UPI）的示例代码。这个插件允许你启动UPI支付意图，让用户能够选择他们的银行应用并完成支付。

首先，确保你已经在你的Flutter项目中添加了get_upi依赖。打开你的pubspec.yaml文件，并添加以下依赖：

dependencies:
  flutter:
    sdk: flutter
  get_upi: ^最新版本号 # 请替换为实际的最新版本号

然后运行flutter pub get来安装依赖。

接下来，你可以在你的Flutter应用中实现UPI支付。以下是一个简单的示例代码：

import 'package:flutter/material.dart';
import 'package:get_upi/get_upi.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter UPI Payment Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: PaymentScreen(),
    );
  }
}

class PaymentScreen extends StatefulWidget {
  @override
  _PaymentScreenState createState() => _PaymentScreenState();
}

class _PaymentScreenState extends State<PaymentScreen> {
  final UpiPlugin _upiPlugin = UpiPlugin();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Flutter UPI Payment Demo'),
      ),
      body: Center(
        child: ElevatedButton(
          onPressed: () async {
            // 配置UPI支付参数
            final UpiPaymentDetails paymentDetails = UpiPaymentDetails(
              receiverUpiId: 'receiver@ybl', // 接收方的UPI ID
              amount: '10.00',               // 支付金额
              transactionNote: 'Demo Payment', // 交易备注
              transactionRef: 'txn12345',     // 交易参考ID
              currencyCode: 'INR',           // 货币代码
              appName: 'Your App Name',      // 你的应用名称（可选）
            );

            try {
              // 启动UPI支付
              final UpiPaymentResponse response = await _upiPlugin.startUpiPayment(
                paymentDetails: paymentDetails,
              );

              // 处理支付结果
              if (response.status == UpiPaymentStatus.success) {
                showDialog(
                  context: context,
                  builder: (BuildContext context) {
                    return AlertDialog(
                      title: Text('Payment Successful'),
                      content: Text('Transaction ID: ${response.transactionId}'),
                      actions: <Widget>[
                        TextButton(
                          onPressed: () {
                            Navigator.of(context).pop();
                          },
                          child: Text('OK'),
                        ),
                      ],
                    );
                  },
                );
              } else if (response.status == UpiPaymentStatus.failed) {
                showDialog(
                  context: context,
                  builder: (BuildContext context) {
                    return AlertDialog(
                      title: Text('Payment Failed'),
                      content: Text(response.errorMessage ?? 'Unknown error'),
                      actions: <Widget>[
                        TextButton(
                          onPressed: () {
                            Navigator.of(context).pop();
                          },
                          child: Text('OK'),
                        ),
                      ],
                    );
                  },
                );
              } else if (response.status == UpiPaymentStatus.cancelled) {
                showDialog(
                  context: context,
                  builder: (BuildContext context) {
                    return AlertDialog(
                      title: Text('Payment Cancelled'),
                      content: Text('User cancelled the payment'),
                      actions: <Widget>[
                        TextButton(
                          onPressed: () {
                            Navigator.of(context).pop();
                          },
                          child: Text('OK'),
                        ),
                      ],
                    );
                  },
                );
              }
            } catch (e) {
              // 处理异常
              showDialog(
                context: context,
                builder: (BuildContext context) {
                  return AlertDialog(
                    title: Text('Error'),
                    content: Text('An error occurred: $e'),
                    actions: <Widget>[
                      TextButton(
                        onPressed: () {
                          Navigator.of(context).pop();
                        },
                        child: Text('OK'),
                      ),
                    ],
                  );
                },
              );
            }
          },
          child: Text('Make Payment'),
        ),
      ),
    );
  }
}

在这个示例中，我们创建了一个简单的Flutter应用，其中包含一个按钮，用户可以点击该按钮来启动UPI支付流程。支付细节（如接收方的UPI ID、支付金额等）通过UpiPaymentDetails对象传递给startUpiPayment方法。支付完成后，根据返回的结果，我们显示相应的对话框来通知用户支付是否成功、失败或被取消。

请确保在实际应用中替换receiver@ybl为实际的接收方UPI ID，并根据需要调整其他支付参数。