Flutter 使用包路径_提供程序后，颤振应用程序崩溃，如何在颤振中修复？

我一直在尝试在Flatter中为本地存储使用json制作一个离线应用程序。我使用了一个包

path\u provider

来获取当前目录应用程序apk。代码如下：-

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'dart:io';
import 'dart:convert';

import 'package:path_provider/path_provider.dart';

class WorkersLog extends StatefulWidget {
  @override
  _WorkersLogState createState() => _WorkersLogState();
}

class _WorkersLogState extends State<WorkersLog> {
  @override
  Widget build(BuildContext context) {
    void _showSettingsPanel() {
      showModalBottomSheet(
          isScrollControlled: true,
          context: context,
          builder: (context) {
            return Container(
              height: MediaQuery.of(context).size.height * .90,
              padding: EdgeInsets.symmetric(vertical: 20.0, horizontal: 40.0),
              child: Center(child: WorkerCardData()),
            );
          });
    }

    return Container(
      child: Column(
        children: [
          SizedBox(height: 40),
          Text(
              "hello there"),
          Row(
            children: <Widget>[
              Center(
                child: Column(
                  children: [
                    SizedBox(height: 370),
                    Row(
                      children: [
                        SizedBox(width: 200),
                        FloatingActionButton.extended(
                          label: Text('add document'),
                          icon: Icon(Icons.save),
                          backgroundColor: Colors.greenAccent,
                          elevation: 5.0,
                          onPressed: () {
                            print('object');
                            _showSettingsPanel();
                          },
                        ),
                      ],
                    ),
                  ],
                ),
              ),
            ],
          ),
        ],
      ),
    );
  }
}

class WorkerCardData extends StatefulWidget {
  @override
  _WorkerCardDataState createState() => _WorkerCardDataState();
}

class _WorkerCardDataState extends State<WorkerCardData> {
  TextEditingController keyInputController = new TextEditingController();
  TextEditingController valueInputController = new TextEditingController();

  File jsonFile;
  Directory dir;
  String fileName = "myFile.json";
  bool fileExists = false;
  Map<String, dynamic> fileContent;

  @override
  void initState() {
    super.initState();
    getApplicationDocumentsDirectory().then((Directory directory) {
      dir = directory;
      jsonFile = new File(dir.path + "/" + fileName);
      fileExists = jsonFile.existsSync();
      if (fileExists)
        this.setState(
            () => fileContent = json.decode(jsonFile.readAsStringSync()));
    });
  }

  @override
  void dispose() {
    keyInputController.dispose();
    valueInputController.dispose();
    super.dispose();
  }

  void createFile(
      Map<String, dynamic> content, Directory dir, String fileName) {
    print("Creating file!");
    File file = new File(dir.path + "/" + fileName);
    file.createSync();
    fileExists = true;
    file.writeAsStringSync(json.encode(content));
  }

  void writeToFile(String key, dynamic value) {
    print("Writing to file!");
    Map<String, dynamic> content = {key: value};
    if (fileExists) {
      print("File exists");
      Map<String, dynamic> jsonFileContent =
          json.decode(jsonFile.readAsStringSync());
      jsonFileContent.addAll(content);
      jsonFile.writeAsStringSync(json.encode(jsonFileContent));
    } else {
      print("File does not exist!");
      createFile(content, dir, fileName);
    }
    this.setState(() => fileContent = json.decode(jsonFile.readAsStringSync()));
    print(fileContent);
  }

  @override
  Widget build(BuildContext context) {
    return Container(
      child: Column(
        children: [
          new Padding(padding: new EdgeInsets.only(top: 10.0)),
          new Text(
            "File content: ",
            style: new TextStyle(fontWeight: FontWeight.bold),
          ),
          new Text(fileContent.toString()),
          new Padding(padding: new EdgeInsets.only(top: 10.0)),
          new Text("Add to JSON file: "),
          new TextField(
            controller: keyInputController,
          ),
          new TextField(
            controller: valueInputController,
          ),
          new Padding(padding: new EdgeInsets.only(top: 20.0)),
          new RaisedButton(
            child: new Text("Add key, value pair"),
            onPressed: () =>
                writeToFile(keyInputController.text, valueInputController.text),
          )
        ],
      ),
    );
  }
}

为什么会产生错误？我如何修复它

我并没有java或android方面的经验，所以若答案是从flatter编码的角度给出的，那个将是很有帮助的

registerResGeneratingTask is deprecated, use registerGeneratedResFolders(FileCollection)
registerResGeneratingTask is deprecated, use registerGeneratedResFolders(FileCollection)
registerResGeneratingTask is deprecated, use registerGeneratedResFolders(FileCollection)
✓ Built build\app\outputs\flutter-apk\app-debug.apk.
E/AndroidRuntime(10874): FATAL EXCEPTION: main
E/AndroidRuntime(10874): Process: com.illuminate.comcrop, PID: 10874
E/AndroidRuntime(10874): java.lang.NoClassDefFoundError: Failed resolution of: Lcom/google/android/gms/common/internal/Preconditions;
E/AndroidRuntime(10874):    at com.google.firebase.provider.FirebaseInitProvider.checkContentProviderAuthority(com.google.firebase:firebase-common@@19.3.0:64)
E/AndroidRuntime(10874):    at com.google.firebase.provider.FirebaseInitProvider.attachInfo(com.google.firebase:firebase-common@@19.3.0:44)
E/AndroidRuntime(10874):    at android.app.ActivityThread.installProvider(ActivityThread.java:7545)
E/AndroidRuntime(10874):    at android.app.ActivityThread.installContentProviders(ActivityThread.java:7090)
E/AndroidRuntime(10874):    at android.app.ActivityThread.handleBindApplication(ActivityThread.java:6978)
E/AndroidRuntime(10874):    at android.app.ActivityThread.access$1300(ActivityThread.java:270)
E/AndroidRuntime(10874):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2051)