Flutter近场服务（NSD）插件nsd_ios的使用

Flutter近场服务（NSD）插件nsd_ios的使用

nsd_ios 是 nsd 插件的 iOS 实现。通过这个插件，你可以在 iOS 设备上使用网络服务发现功能。

安装插件

首先，在你的 pubspec.yaml 文件中添加 nsd 插件依赖：

dependencies:
  flutter:
    sdk: flutter
  nsd: ^0.1.0

然后运行 flutter pub get 命令来安装插件。

使用示例

以下是一个简单的示例，演示如何在 iOS 设备上使用 nsd_ios 插件进行服务发现。

发布服务

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

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

class MyApp extends StatelessWidget {
  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: Text('NSD Example')),
        body: Center(child: PublishServiceButton()),
      ),
    );
  }
}

class PublishServiceButton extends StatefulWidget {
  [@override](/user/override)
  _PublishServiceButtonState createState() => _PublishServiceButtonState();
}

class _PublishServiceButtonState extends State<PublishServiceButton> {
  bool isServicePublished = false;

  void publishService() async {
    try {
      await Nsd.publish(
        name: 'MyService',
        type: '_http._tcp.',
        port: 8080,
      );
      setState(() {
        isServicePublished = true;
      });
    } catch (e) {
      print('Failed to publish service: $e');
    }
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    return ElevatedButton(
      onPressed: publishService,
      child: Text(isServicePublished ? '服务已发布' : '发布服务'),
    );
  }
}

发现服务

class DiscoverServicesButton extends StatefulWidget {
  [@override](/user/override)
  _DiscoverServicesButtonState createState() => _DiscoverServicesButtonState();
}

class _DiscoverServicesButtonState extends State<DiscoverServicesButton> {
  List<String> discoveredServices = [];

  void discoverServices() async {
    try {
      final List<String> services = await Nsd.discover(
        type: '_http._tcp.',
      );

      setState(() {
        discoveredServices = services;
      });
    } catch (e) {
      print('Failed to discover services: $e');
    }
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    return ElevatedButton(
      onPressed: discoverServices,
      child: Text('发现服务'),
    );
  }
}

class ServiceList extends StatelessWidget {
  final List<String> services;

  ServiceList({required this.services});

  [@override](/user/override)
  Widget build(BuildContext context) {
    return ListView.builder(
      itemCount: services.length,
      itemBuilder: (context, index) {
        return ListTile(
          title: Text(services[index]),
        );
      },
    );
  }
}

将上述两个按钮组件集成到主页面：

class MyApp extends StatelessWidget {
  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: Text('NSD Example')),
        body: Padding(
          padding: const EdgeInsets.all(16.0),
          child: Column(
            children: [
              PublishServiceButton(),
              SizedBox(height: 20),
              DiscoverServicesButton(),
              SizedBox(height: 20),
              ServiceList(services: discoveredServices),
            ],
          ),
        ),
      ),
    );
  }
}