json - 错误: 'List' is not a subtype of type 'Map'

Question

我试图在用户输入电子邮件和密码后获取用户信息。我正在使用的 API 返回用户的额外信息，因此我尝试获取该信息作为开始。

我正在尝试解析这个 json:

[
    {
        "_user": {
            "id": "id-here",
            "name": "Mobile",
            "email": "<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="44292b262d28216a31372136042537206a272b29" rel="noreferrer noopener nofollow">[email protected]</a>",
            "photo": null,
            "title": null,
            "surname": "User",
            "bg_photo": null,
            "isactive": true,
            "password": "123456789",
            "username": "mobileuser",
            "checkInfo": true,
            "role_type": "asd",
            "profession": null,
            "isemailverify": false
        },
        "tokens": {
            "accessToken": "someTokenhere",
            "refreshToken": "anotherOne"
        }
    }
]

这些是我的模型:

class User {
  User({
    this.user,
    this.tokens,
  });

  UserClass user;
  Tokens tokens;

  factory User.fromJson(Map<String, dynamic> json){
    return User(
      user: UserClass.fromJson(json["_user"]),
      tokens: Tokens.fromJson(json["tokens"]),
    );
  }
}

class Tokens {
  Tokens({
    this.accessToken,
    this.refreshToken,
  });

  String accessToken;
  String refreshToken;

  factory Tokens.fromJson(Map<String, dynamic> json) => Tokens(
    accessToken: json["accessToken"],
    refreshToken: json["refreshToken"],
  );
}

class UserClass {
  UserClass({
    this.id,
    this.name,
    this.email,
    this.photo,
    this.title,
    this.surname,
    this.bgPhoto,
    this.isactive,
    this.password,
    this.username,
    this.checkInfo,
    this.roleType,
    this.profession,
    this.isemailverify,
  });

  String id;
  String name;
  String email;
  String photo;
  String title;
  String surname;
  String bgPhoto;
  bool isactive;
  String password;
  String username;
  bool checkInfo;
  String roleType;
  String profession;
  bool isemailverify;

  factory UserClass.fromJson(Map<String, dynamic> json) => UserClass(
    id: json["id"],
    name: json["name"],
    email: json["email"],
    photo: json["photo"],
    title: json["title"],
    surname: json["surname"],
    bgPhoto: json["bg_photo"],
    isactive: json["isactive"],
    password: json["password"],
    username: json["username"],
    checkInfo: json["checkInfo"],
    roleType: json["role_type"],
    profession: json["profession"],
    isemailverify: json["isemailverify"],
  );
}

这是我发送电子邮件、密码和获取用户数据的部分:

Future<User> checkUserExist(String email, String password) async {
    final response = await http.post(
      Uri.https('SomeApi', 'Route'),
      headers: <String, String>{
        'Content-Type': 'application/json; charset=UTF-8',
      },
      body: jsonEncode(<String, String>{
        'email': email,
        'password': password
      }),
    );
    if (response.statusCode == 200) {
      return User.fromJson(jsonDecode(response.body));
    } else {
      throw Exception(jsonDecode(response.body));
    }
  }

这是给我错误的部分

if (response.statusCode == 200) {
      return User.fromJson(jsonDecode(response.body));
} 

我打印了响应正文，它给了我我想要的东西 - 字符串 - 但 jsonDecode 返回一个列表，所以我无法使用它。我怎样才能解决这个问题？提前致谢。

Answer 1

改变这个

return User.fromJson(jsonDecode(response.body))

对此:

return User.fromJson(jsonDecode(response.body)[0])

原因是你每件事都做得很完美，直到最后一步。如果仔细查看您的响应，它确实有一个映射或 _user 和 token，但该映射实际上位于列表内，请注意方括号 [ ] 围绕 {}。

您需要访问的 map 位于此列表的索引[0]处，那么一切都会正常工作。