提供了包含您的代码的基本HelloWorld Flutter示例。我为将来增加了一个延迟，以便ProgressIndicator显示两秒钟。像我想要的那样工作：

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',home: MyHomePage(title: 'Flutter Demo Home Page'),);
  }
}

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

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

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;
  Map<String,bool> students;

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),),body: FutureBuilder(
          future: GetInfoFromBackEnd(),builder: (BuildContext context,AsyncSnapshot<Map> snapshot) {
            return snapshot.hasData
                ? new Text(snapshot.data.toString())
                : new CircularProgressIndicator();
          }),floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,tooltip: 'Increment',child: Icon(Icons.add),);
  }

  Future<Map> GetInfoFromBackEnd() async {
    return Future.delayed(Duration(seconds: 2),() {
      students = {
        'this info should be taken from backend0': false,'this info should be taken from backend1': false,'this info should be taken from backend2': false,'this info should be taken from backend3': false,'this info should be taken from backend4': false,};
      return students;
    });
  }
}

问题不在FutureBuilder或地图中，实际上，当我尝试获取学生Map值和List中的每个键时，它破坏了Future并阻止了它返回Corret值，因此快照中没有null。数据;这是我如何修复它：

studentsList = students.keys.toList();
studentsCheck = students.values.toList();
return students;

P.S。 ：错误为type '_CompactIterable<String>' is not a subtype of type 'List<String>'