参数类型 'dynamic' 无法分配给参数类型 'Map<String, dynamic>'

Question

final dataResponse = await http.get(Uri.parse('https://jsonplaceholder.typicode.com/albums/1'));
    Album.fromJson(jsonDecode(dataResponse.body));

在启用 nullsafety 的项目上，Album.fromJson(jsonDecode(dataResponse.body)); 此代码抛出错误 The argument type 'dynamic' can't be assigned to the parameter type 'Map<String, dynamic>'.

已关注官方doc

以下代码用于数据建模。

class Album {
  final int userId;
  final int id;
  final String title;

  Album({
    required this.userId,
    required this.id,
    required this.title,
  });

  factory Album.fromJson(Map<String, dynamic> json) {
    return Album(
      userId: json['userId'],
      id: json['id'],
      title: json['title'],
    );
  }
}

Answer 1

只需要将 (Map json) 更改为 (dynamic json)

factory Album.fromJson(dynamic json) {
    return Album(
      userId: json['userId'],
      id: json['id'],
      title: json['title'],
    );
  }

Answer 2

模型已经不错了...

试试这个。

final dataResponse = await http.get(Uri.parse('https://jsonplaceholder.typicode.com/albums/1'));
List<dynamic> list =jsonDecode(dataResponse.body);
return list.map((e)=>Album.fromJson(e)).toList();

Answer 3

你只需要投射你的jsonDecode

Album.fromJson(jsonDecode(dataResponse.body));

显式类型：

Album.fromJson(jsonDecode(dataResponse.body) as Map<String, dynamic>);

参数类型 'dynamic' 无法分配给参数类型 'Map<String, dynamic>'

The argument type 'dynamic' can't be assigned to the parameter type 'Map<String, dynamic>'

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