Flutter TCP通信

启动TCP服务

  Future startServer() async {
    final server = await ServerSocket.bind(InternetAddress.anyIPv4, 12345);
    print('Server listening on ${server.address}:${server.port}');

    server.listen((Socket socket) {
      print('Client connected: ${socket.remoteAddress.address}');

      socket.listen(
            (data) {
          final message = String.fromCharCodes(data);
          print('Received: $message');
          socket.write('Echo: $message');
        },
        onDone: () => print('Client disconnected'),
      );
    });
  }

连接TCP服务

    try {
      final socket = await Socket.connect(ip, 12345/*, timeout: Duration(seconds: 3)*/);
      print('Connected to server');

      socket.listen(
        (data) {
          print('Server response: ${String.fromCharCodes(data)}');
        },
        onDone: () => socket.destroy(),
      );
      print("send message");
      _socket = socket;
      socket.write('Hello from Flutter client!');

    } catch (e) {
      print('Error: $e');
    }

很简单个功能，居然遇上问题了：iOS启动服务异常，作为客户端连接其他服务也不行，折腾了两天发现，是因为设置的系统版本低于iOS13.0，在Xcode中把 Minimum Deployments 改成13.0就可以了。