flutter_bluetooth_serial 错误状态：流已经被监听

Question

import 'package:flutter_bluetooth_serial/flutter_bluetooth_serial.dart';
class Light extends StatefulWidget {
  final connection;
  Light(this.connection);
  @override
  LightState createState() => LightState(connection);
}

class LightState extends State<Light> {
  final BluetoothConnection connection;
  var controller = BehaviorSubject();
  LightState(this.connection);

  double depth = 10;
  int lightValue = 580;
  Color color = Colors.white54;

  Color currentColor = Colors.limeAccent;
  void changeColor(Color color) => setState(() => currentColor = color);

  @override
  void initState() {
    super.initState();

    if (connection != null) {
      if (!connection.input.isBroadcast) {
        var listen = connection.input.asBroadcastStream();
        listen.listen((data) {
          setState(() {
            lightValue = data[0];
          });
          print(lightValue);
        });
      }
    }
  }

  @override
  void dispose() async {
    super.dispose();
    await connection.close();
    connection.dispose();
  }


  @override
  Widget build(BuildContext context) {
    final size = 200.0;
    return Scaffold(
      appBar: AppBar(
        centerTitle: true,
        title: Text("Light"),
        backgroundColor: Colors.black,
      ),
      body: Container(
        decoration: BoxDecoration(
            gradient: LinearGradient(
          begin: Alignment.topLeft,
          end: Alignment.bottomRight,
          colors: [
            Color(0xff323232),
            Color(0xff050505),
          ],
        )),
        child: Stack(
          children: [
            Center(
              child: Container(
                width: size,
                height: size,
                decoration: BoxDecoration(
                    borderRadius: BorderRadius.all(Radius.circular(100)),
                    boxShadow: [
                      BoxShadow(
                        offset: Offset(1, 1),
                        color: color,
                        blurRadius: 50,
                        spreadRadius: 1,
                      ),
                    ]),
                child: Stack(
                  children: [
                    ShaderMask(
                      shaderCallback: (rect) {
                        return LinearGradient(
                                transform: GradientRotation(-1.5708),
                                stops: [lightValue / 255, 0],
                                colors: [Color(0xff010e80), Colors.transparent])
                            .createShader(rect);
                      },
                      child: Container(
                        width: size,
                        height: size,
                        decoration: BoxDecoration(
                            shape: BoxShape.circle, color: Colors.white),
                      ),
                    ),
                  ],
                ),
              ),
            ),
          ),
        ],
      ),
    );
  } 
}

当您以这种方式连接到蓝牙时，连接是在另一个小部件中定义的：

await BluetoothConnection.toAddress(_device.address)
            .then((_connection) {
          print('Connected to the device');
          connection = _connection;
          setState(() {
            _connected = true;
          });

然后此连接通过构造函数发送到 Light StatefulWidget。
该小部件在单击时打开，在我离开并再次打开它后给出 Bad State: Stream has already been listened to.。
我已经尝试使用 StreamBuilder 但它给出了同样的错误。
我已经查看了相关问题，有人指出使用广播或 BehaviorSubject。但是我找不到将它们与 bluetooth_serial 包一起使用的方法。