Flutter USSD服务插件ussd_service的使用

插件简介

ussd_service插件使Flutter应用程序能够调用Android的sendUssdRequest方法。

安装

在您的pubspec.yaml文件中添加ussd_service作为依赖项。同时，请确保您的AndroidManifest.xml文件包含以下权限：

<uses-permission android:name="android.permission.CALL_PHONE" />

使用说明

在使用此插件之前，您需要确保：

• 用户已授权访问电话权限，例如通过permission_handler插件。
• 获取SIM卡的订阅ID，例如通过sim_data插件。

然后您可以按照以下方式使用插件：

示例代码

import 'dart:async';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:permission_handler/permission_handler.dart';
import 'package:sim_data/sim_data.dart';
import 'package:ussd_service/ussd_service.dart';

void main() => runApp(const MyApp());

class MyApp extends StatefulWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  _MyAppState createState() => _MyAppState();
}

enum RequestState {
  ongoing,
  success,
  error,
}

class _MyAppState extends State<MyApp> {
  RequestState? _requestState;
  String _requestCode = "";
  String _responseCode = "";
  String _responseMessage = "";

  Future<void> sendUssdRequest() async {
    setState(() {
      _requestState = RequestState.ongoing;
    });
    try {
      String responseMessage;
      await Permission.phone.request();
      if (!await Permission.phone.isGranted) {
        throw Exception("permission missing");
      }

      SimData simData = await SimDataPlugin.getSimData();
      responseMessage = await UssdService.makeRequest(
          simData.cards.first.subscriptionId, _requestCode);
      setState(() {
        _requestState = RequestState.success;
        _responseMessage = responseMessage;
      });
    } on PlatformException catch (e) {
      setState(() {
        _requestState = RequestState.error;
        _responseCode = e is PlatformException ? e.code : "";
        _responseMessage = e.message ?? '';
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Ussd Plugin demo'),
        ),
        body: Container(
          padding: const EdgeInsets.symmetric(vertical: 10, horizontal: 20),
          child: Column(
              crossAxisAlignment: CrossAxisAlignment.stretch,
              children: <Widget>[
                TextFormField(
                  decoration: const InputDecoration(
                    labelText: 'Enter Code',
                  ),
                  onChanged: (newValue) {
                    setState(() {
                      _requestCode = newValue;
                    });
                  },
                ),
                const SizedBox(height: 20),
                MaterialButton(
                  color: Colors.blue,
                  textColor: Colors.white,
                  onPressed: _requestState == RequestState.ongoing
                      ? null
                      : () {
                          sendUssdRequest();
                        },
                  child: const Text('Send Ussd request'),
                ),
                const SizedBox(height: 20),
                if (_requestState == RequestState.ongoing)
                  Row(
                    children: const <Widget>[
                      SizedBox(
                        width: 24,
                        height: 24,
                        child: CircularProgressIndicator(),
                      ),
                      SizedBox(width: 24),
                      Text('Ongoing request...'),
                    ],
                  ),
                if (_requestState == RequestState.success) ...[
                  const Text('Last request was successful.'),
                  const SizedBox(height: 10),
                  const Text('Response was:'),
                  Text(
                    _responseMessage,
                    style: const TextStyle(fontWeight: FontWeight.bold),
                  ),
                ],
                if (_requestState == RequestState.error) ...[
                  const Text('Last request was not successful'),
                  const SizedBox(height: 10),
                  const Text('Error code was:'),
                  Text(
                    _responseCode,
                    style: const TextStyle(fontWeight: FontWeight.bold),
                  ),
                  const SizedBox(height: 10),
                  const Text('Error message was:'),
                  Text(
                    _responseMessage,
                    style: const TextStyle(fontWeight: FontWeight.bold),
                  ),
                ]
              ]),
        ),
      ),
    );
  }
}

注意事项

• Android的sendUssdRequest方法不支持交互式或多步骤的USSD会话，因此这个插件也不支持它们。不过，可以通过将所有参数合并到一个USSD请求中来实现类似的行为，例如：*firstCode*2ndCode*3rdCode*4thCode*..*..#。

总结

以上就是关于ussd_service插件的基本使用方法和注意事项。希望对您有所帮助！如果有任何问题或建议，欢迎随时提问。