无法在隔离内执行Firebase查询

Question

我正在用颤音开发一个应用程序。我想使用隔离来执行一些Firebase查询。但是每次我运行这个应用程序时，我都会看到这个错误，没有显示任何内容。

这是我的代码

class HomePage extends StatefulWidget {
    HomePage({Key key, this.title}) : super(key: key);
    final String title;

    @override
    HomePageState createState() => HomePageState();
 }


class HomePageState extends State<HomePage>{
    Isolate _isolate;
    ReceivePort _receivePort;
    String _data;

  @override
  Widget build(BuildContext context){
    return WillPopScope(
    child: Scaffold(){
     child : Center(child:Text('${_data}'))
     });
  }


 //To start
  void _start() async {
  _receivePort = ReceivePort();
  _isolate = await Isolate.spawn(getData, _receivePort.sendPort);
  _receivePort.listen(_displayData, onDone: () {
     print("done!");
  });
}

 //Display data;
void _displayData(dynamic data) {
  setState(() {
    _data = data;
  });
 }

  static void getData(SendPort sendPort) async{
   var fire = Firestore.instance;
   fire.settings(persistenceEnabled: true); //I get an error here
   fire.document('MODEL/${id}')
    .snapshots()
    .listen((d) {//I get an error here
     sendPort.send(d);
    }
 }
}

 //I call the method _start in the initState
@override
 void initState() {
    _start();
   super.initState();
  }

，这是我得到的错误

未处理异常:E/

(14817)：错误:本机函数'Window_sendPlatformMessage‘(4个参数)：#0 Window.sendPlatformMessage (dart:ui/window.dart:1133:9) E/Window.sendPlatformMessage (14817)：#1 _DefaultBinaryMessenger._sendPlatformMessage _DefaultBinaryMessenger._sendPlatformMessage15) E/ (package:flutter/src/services/platform_channel.dart:309:51) (14817)：#2 _DefaultBinaryMessenger.send _DefaultBinaryMessenger.send E/颤振(14817)：#3 MethodChannel.invokeMethod MethodChannel.invokeMethod E/颤振(14817)：E/颤振(14817)：#4 Query.snapshots。(package:cloud_firestore/src/query.dart:61:37) E/颤振(14817)：#5 _runGuarded (飞镖:异步/流_能控器。飞镖:805:24)E/颤振(14817)：#6 _BroadcastStreamController._subscribe _BroadcastStreamController._subscribe E/颤振(14817)：#7 _ControllerStream._createSubscription (飞镖:异步/流_能控器:818:19))E/颤振(14817)：E/颤振(14817)：#4 (package:cloud_firestore/src/firestore.dart:154:19) E/颤振(14817)：E/颤振(14817)：#5 HomePageState.getData (package:flutter_app/HelpFile/HomePage.dart:207:10) E/颤振(14817)：#8 _StreamImpl.listen (省道: Firestore.settings /Firestore.settings_INPRIN.DAT:472:9) E/颤振(14817)：#9 HomePageState.getData (包装:flutter_app/HomePage.Dart:201:10)E/颤振(14817)：E/颤振(14817)：#10 _startIsolate。(dart:isolate-patch/isolate_patch.dart:308:17) E/颤振(14817)：#11 _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:172:12)

Answer 1

检查这个链接https://firebase.google.com/docs/reference/android/com/google/firebase/FirebaseApp

任何FirebaseApp初始化只能在应用程序的主进程中进行。不支持在主进程以外的进程中使用Firebase，并且可能会导致与资源争用相关的问题。