Fresh Flutter项目出现错误：未定义函数“ runApp”

Question

我正在尝试使用flutter create app_name来测试抖动，并使用Android Studio和VS Code我未定义runApp上的错误，并且在Flutter库中的任何地方我都看不到它正在定义。

奇怪的是，我第一次创建模板应用程序时，它在导入库中具有不同的模板和更多行，但是在第二次尝试后，导入行仅限于：import 'package:flutter/material.dart';，其中当然不包括{{1 }}

runApp()

错误

import 'package:flutter/material.dart';


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

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        // This is the theme of your application.
        //
        // Try running your application with "flutter run". You'll see the
        // application has a blue toolbar. Then, without quitting the app, try
        // changing the primarySwatch below to Colors.green and then invoke
        // "hot reload" (press "r" in the console where you ran "flutter run",
        // or simply save your changes to "hot reload" in a Flutter IDE).
        // Notice that the counter didn't reset back to zero; the application
        // is not restarted.
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

Answer 1

显然SDK中存在损坏的文件，请通过C:\src\flutter重新安装SDK来解决此问题。