无法通过蓝牙与 flutter_reactive_ble 连接答案

【问题标题】：Trouble to connect via bluetooth with flutter_reactive_ble无法通过蓝牙与 flutter_reactive_ble 连接
【发布时间】：2022-08-17 23:27:14
【问题描述】：

？？？大家好！

我目前正在使用包flutter_reactive_ble

但我正在努力使连接保持一致

昨天我认为问题肯定来自：

if (connectionState.connectionState == DeviceConnectionState.connected)

因为大多数时候它以“正在连接”的形式出现，但是如果它以“正在连接”的形式出现而不像睡眠一样检查循环，我不确定如何等到它连接，这里的目标是快速，所以用户体验很好

我正在做一个麦克M1？？？并测试安卓？？？

附言: 代码不干净，但目标是让它工作。 ⚙️

希望有人能帮忙？？？


import \'dart:io\';
import \'dart:typed_data\';
import \'package:flutter/material.dart\';
import \'package:flutter_reactive_ble/flutter_reactive_ble.dart\';
import \'package:permission_handler/permission_handler.dart\';
import \'package:qrcode/enum/characteristic_enum.dart\';

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

  @override
  State<CadenaData> createState() => _CadenaDataState();
}

class _CadenaDataState extends State<CadenaData> {
  final flutterReactiveBle = FlutterReactiveBle();

  @protected
  @mustCallSuper


  void findCadena(BuildContext context) async {
    flutterReactiveBle.connectToDevice(
      id: \"DC:30:FC:9F:45:91\",
      connectionTimeout: const Duration(seconds: 10),
    ).listen(
      (connectionState) async {
        if (connectionState.connectionState ==   DeviceConnectionState.connected) {

    //doing stuff
         
        } else {
          print(\"connection failed\\n $connectionState.connectionState\");
        };
      },
      onError: (error) {
        print(\"error on connect $error\");
      },
    );
  }

标签： flutter dart asynchronous bluetooth-lowenergy

【解决方案1】：

我用接收“FlutterReactiveBle.connectToDevice()”结果的“StreamSubscription”解决了我的问题

还有一个 switch case 来管理流的不同输出。

late StreamSubscription<dynamic> _currentConnectionStream;

 _currentConnectionStream = flutterReactiveBle
    .connectToDevice(
  id: "DC:30:FC:9F:45:91",
  connectionTimeout: const Duration(seconds: 15),
)
    .listen(
  (connectionState) async {

    switch (connectionState.connectionState) {
      case DeviceConnectionState.connecting:
        print("-- Connecting to device --");
        break;

      case DeviceConnectionState.connected:
        print(" -- Connected --");
        break;

      case DeviceConnectionState.disconnecting:
        print("-- disconnecting --");
        break;

      case DeviceConnectionState.disconnected:
        print("-- disconnected --");
        break;
    }
  },
  onError: (error) {
    print("error on connect $error \n");
  },
);

【讨论】：