listenRead method
监听读取characteristic值的请求
Implementation
StreamSubscription listenRead(void Function(KGattDevice device, int requestId, int offset) onRead) {
return KGattHandler()
.eventStream
.where((event) => event['event'] == 'CharacteristicReadRequest' && event["entityId"] == entityId)
.listen((event) {
print(event);
print(_entityId);
final device = KGattDevice.fromMap(Map.from(event['device']));
onRead(device, event['requestId'], event['offset']);
});
}