相关疑难解决方法(0)

我目前在获取Provider' value ininitstate`时遇到问题。

我想在 Appbar 和 body 中的其他部分的下拉列表中设置默认值。但我有一个错误说dependOnInheritedElement() was called before initstate() in flutter.

我的完整代码如下

main.dart

import 'package:test_eoil/model/button_data.dart';
import 'package:test_eoil/model/output_data.dart';
import 'screen/screen.dart';
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';


void main() => runApp(new MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MultiProvider(providers: [
//      ChangeNotifierProvider<ChordData>(create: (context) => ChordData()),
      ChangeNotifierProvider<OutputData>(create: (context) => OutputData()),
      ChangeNotifierProvider<ButtonData>(create: (context) => ButtonData())
    ],
      child: MaterialApp(
        home: Screen(),
      ),
    );
  }
}

screen.dart 在屏幕文件夹中

import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:test_eoil/model/button_data.dart';
import 'package:test_eoil/model/output_data.dart'; …