未处理的异常：键入“列表”<dynamic> &#39; 不是类型 &#39;Map 的子类型<dynamic, dynamic>

Question

I'm trying to get the data from an API and store it in a map so I can use it.

It worked here...

class _LoadingState extends State<Loading> {
  void getData() async {
    Response response =
        await get(Uri.parse("https://jsonplaceholder.typicode.com/todos/1"));
    Map data = jsonDecode(response.body);
    print(data);
    print(data["title"]);
  }

  @override
  void initState() {
    super.initState();
    getData();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Text("loading screen"),
    );
  }
}

Output:

I/flutter ( 8199): {userId: 1, id: 1, title: delectus aut autem, completed: false}
I/flutter ( 8199): delectus aut autem

But when I try it with the WorldTimeAPI I get an error.

Code:

class _LoadingState extends State<Loading> {
  void getTime() async {
    Response response =
        await get(Uri.parse("http://worldtimeapi.org/api/timezone/Europe"));
    Map data = jsonDecode(response.body);
    print(data);
  }

  @override
  void initState() {
    super.initState();
    getTime();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Text("loading screen"),
    );
  }
}

Error:

Restarted application in 546ms.
E/flutter ( 8199): [ERROR:flutter/lib/ui/ui_dart_state.cc(199)] Unhandled Exception: type 'List<dynamic>' is not a subtype of type 'Map<dynamic, dynamic>'
E/flutter ( 8199): #0      _LoadingState.getTime
package:world_time/pages/loading.dart:14
E/flutter ( 8199): <asynchronous suspension>
E/flutter ( 8199):

I have tried to find out a solution with similar questions but could not fix it.

Answer 1

The json that the Api provides is not a Map but a List.

JSON List structure

[
  "Europe/Amsterdam",
  "Europe/Andorra",
  "Europe/Astrakhan",
....
]

This would be a List of the Type dynamic

Flutter code

  void getTime() async {
    Response response =
        await get(Uri.parse("http://worldtimeapi.org/api/timezone/Europe"));
    List<dynamic> data = jsonDecode(response.body);
    print(data);
  }

JSON Map structure

{
  "userId": 1,
  "id": 1,
  "title": "delectus aut autem",
  "completed": false
}

This would be a Map of the Type String,dynamic

Flutter code

  void getData() async {
    Response response =
        await get(Uri.parse("https://jsonplaceholder.typicode.com/todos/1"));
    Map<String, dynamic> data = jsonDecode(response.body);
    print(data);
  }