Why I got : Error: MissingPluginException(No implementation found for method startScan on channel flutter_bluetooth_brazilian/methods)? - flutter

Question

I'm trying to connect devices with Bluetooth and then share data. The problem now is that I always get: Missing Plugin Exception for flutter_bluetooth bluetooth_Brazilian.
this is bluetooth_manager.dart code:
import 'dart:async';
import 'package:flutter/services.dart';
import 'package:rxdart/rxdart.dart';
import 'bluetooth_device.dart';
/// A BluetoothManager.
class BluetoothManager {
static const String NAMESPACE = 'flutter_bluetooth_brazilian';
static const int CONNECTED = 1;
static const int DISCONNECTED = 0;
static const MethodChannel _channel =
const MethodChannel('$NAMESPACE/methods');
static const EventChannel _stateChannel =
const EventChannel('$NAMESPACE/state');
Stream<MethodCall> get _methodStream => _methodStreamController.stream;
final StreamController<MethodCall> _methodStreamController =
StreamController.broadcast();
BluetoothManager._() {
_channel.setMethodCallHandler((MethodCall call) {
_methodStreamController.add(call);
return;
});
}
static BluetoothManager _instance = BluetoothManager._();
static BluetoothManager get instance => _instance;
// Future<bool> get isAvailable async =>
// await _channel.invokeMethod('isAvailable').then<bool>((d) => d);
// Future<bool> get isOn async =>
// await _channel.invokeMethod('isOn').then<bool>((d) => d);
Future<bool> get isConnected async =>
await _channel.invokeMethod('isConnected');
BehaviorSubject<bool> _isScanning = BehaviorSubject.seeded(false);
Stream<bool> get isScanning => _isScanning.stream;
BehaviorSubject<List<BluetoothDevice>> _scanResults =
BehaviorSubject.seeded([]);
Stream<List<BluetoothDevice>> get scanResults => _scanResults.stream;
PublishSubject _stopScanPill = new PublishSubject();
/// Gets the current state of the Bluetooth module
Stream<int> get state async* {
yield await _channel.invokeMethod('state').then((s) => s);
yield* _stateChannel.receiveBroadcastStream().map((s) => s);
}
/// Starts a scan for Bluetooth Low Energy devices
/// Timeout closes the stream after a specified [Duration]
Stream<BluetoothDevice> scan({
Duration timeout,
}) async* {
if (_isScanning.value == true) {
throw Exception('Another scan is already in progress.');
}
// Emit to isScanning
_isScanning.add(true);
final killStreams = <Stream>[];
killStreams.add(_stopScanPill);
if (timeout != null) {
killStreams.add(Rx.timer(null, timeout));
}
// Clear scan results list
_scanResults.add(<BluetoothDevice>[]);
try {
await _channel.invokeMethod('startScan');
} catch (e) {
print('Error starting scan.');
_stopScanPill.add(null);
_isScanning.add(false);
throw e;
}
yield* BluetoothManager.instance._methodStream
.where((m) => m.method == "ScanResult")
.map((m) => m.arguments)
.takeUntil(Rx.merge(killStreams))
.doOnDone(stopScan)
.map((map) {
final device = BluetoothDevice.fromJson(Map<String, dynamic>.from(map));
final List<BluetoothDevice> list = _scanResults.value;
int newIndex = -1;
list.asMap().forEach((index, e) {
if (e.address == device.address) {
newIndex = index;
}
});
if (newIndex != -1) {
list[newIndex] = device;
} else {
list.add(device);
}
_scanResults.add(list);
return device;
});
}
Future startScan({
Duration timeout,
}) async {
await scan(timeout: timeout).drain();
return _scanResults.value;
}
/// Stops a scan for Bluetooth Low Energy devices
Future stopScan() async {
await _channel.invokeMethod('stopScan');
_stopScanPill.add(null);
_isScanning.add(false);
}
Future<dynamic> connect(BluetoothDevice device) =>
_channel.invokeMethod('connect', device.toJson());
Future<dynamic> disconnect() => _channel.invokeMethod('disconnect');
Future<dynamic> destroy() => _channel.invokeMethod('destroy');
Future<dynamic> writeData(List<int> bytes) {
Map<String, Object> args = Map();
args['bytes'] = bytes;
args['length'] = bytes.length;
_channel.invokeMethod('writeData', args);
return Future.value(true);
}
}

Answer 1

flutter_bluetooth_brazilian doesn't support the web platform. You can check the supported platforms right on the plugin's page at https://pub.dev.