flutter - 类型 '_InternalLinkedHashMap' 不是使用 http 包的类型 'String' 的子类型

Question

我正在尝试从链接中获取数据。链接在这里: -“https://wreSTLingworld.co/wp-json/wp/v2/posts?categories=22”

获取时出现错误。我尝试了一些不同的方法来做到这一点，但找不到准确的解决方案。我附上了我的代码，我为解决问题所做的尝试。

这是我的 Controller :

class NewsController{
  String url = "https://wrestlingworld.co/wp-json/wp/v2/posts?categories=22";
  Future<List> getNews() async {
    try{
      var response = await http.get(Uri.parse(url));
      if(response.statusCode == 200){
        print(response.body);
        // Map<String, dynamic> resp = json.decode(response.body);
        return json.decode(response.body);
        // return Map<String, dynamic> json.decode(response.body);
      }
      else{
        return Future.error("Error Handling the request");
      }
    } catch(Exception){
      print(Exception);
      return Future.error("Error in the controller");
    }
  }
}

这是我的模型:

class NewsModel {
  late int id;
  late String date;
  late String status;
  late String type;
  late String link;
  late String title;
  late String content;

  NewsModel(
      {
        required this.id,
        required this.date,
        required this.status,
        required this.type,
        required this.link,
        required this.title,
        required this.content});

  NewsModel.fromJson(Map<String, dynamic> json) {
    id = json['id'];
    date = json['date'];
    status = json['status'];
    type = json['type'];
    link = json['link'];
    title = json['title'];
    content = json['content'];
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['id'] = this.id;
    data['date'] = this.date;
    data['status'] = this.status;
    data['type'] = this.type;
    data['link'] = this.link;
    if (this.title != null) {
      data['title'] = this.title;
    }
    if (this.content != null) {
      data['content'] = this.content;
    }
    return data;
  }
}

这里是我要获取的地方:

FutureBuilder(
  future: newsController.getNews(),
  builder: (context, snapShot) {
    if (snapShot.hasData) {
      return Padding(
        padding: const EdgeInsets.all(8.0),
          child: ListView.builder(
              scrollDirection: Axis.vertical,
              shrinkWrap: true,
              itemCount: snapShot.data?.length,
              itemBuilder: (context, item){
                return NewsCard(title: snapShot.data?[item]['title']);
          })
      );
    }
    else {
      return const Center(child: CircularProgressIndicator());
    }
  },
),

在尝试获取时出现此错误:type '_InternalLinkedHashMap ' is not a subtype of type 'String'

有什么办法可以解决这个问题吗？

我尝试在不使用 Future 的情况下编写函数，但它根本不起作用。所以我想使用相同的函数获取数据。

Answer 1

您在从 map 构造数据时犯了一些错误。 This site有助于查看 http 请求的完整响应。

在您的情况下，以下数据类应该有所帮助:

class YourModel {
  final int id;
  final String date;
  final String status;
  final String type;
  final String link;
  final String title;
  final String content;

  YourModel({
    required this.id,
    required this.date,
    required this.status,
    required this.type,
    required this.link,
    required this.title,
    required this.content,
  });

  factory YourModel.fromJson(Map<String, dynamic> json) {
    return YourModel(
      id: json['id'],
      date: json['date'],
      status: json['status'],
      type: json['type'],
      link: json['link'],
      title: json['title']['rendered'],
      content: json['content']['rendered'],
    );
  }
}

也为您的代码尝试这些:

FutureBuilder(
  future: newsController.getNews(),
  builder: (context, snapShot) {
    if (snapShot.hasData) {
      return Padding(
        padding: const EdgeInsets.all(8.0),
          child: ListView.builder(
              scrollDirection: Axis.vertical,
              shrinkWrap: true,
              itemCount: snapShot.data?.length,
              itemBuilder: (context, item){
                return NewsCard(title: snapShot.data?[item]['title']['rendered']);
          })
      );
    }
    else {
      return const Center(child: CircularProgressIndicator());
    }
  },
),