list - Flutter - 参数类型“Iterable>”不能分配给类型“List”

Question

我想在每个 api 调用中再获得 5 条记录并将它们添加到现有列表中。但是，下面的结构给出了错误。错误屏幕截图和完整的代码结构如下所示。

探索页面初始化

 @override
  void initState() {
        exploreController.fetchArticles(offsetCount: page);
    super.initState();
    _sc.addListener(() {
      if (_sc.position.pixels == _sc.position.maxScrollExtent) {
        page = page + 5;
        exploreController.fetchArticles(offsetCount: page);
      }
    });
  }

探索模型

List<ExploreModel> exploreModelFromJson(String str) => List<ExploreModel>.from(
    json.decode(str).map((x) => ExploreModel.fromJson(x)));

String exploreModelToJson(List<ExploreModel> data) =>
    json.encode(List<dynamic>.from(data.map((x) => x.toJson())));

我的 api 调用

static Future<List<ExploreModel>> fetchArticleList(int offsetCount) async {
    var url = Uri.http(Config().baseUrl, Config().baseUrlPathGetArticles,
        {'offsetCount': '$offsetCount'});
    var response = await http.get(url);
    if (response.statusCode == 200) {
      return exploreModelFromJson(utf8.decode(response.bodyBytes));
    } else {
      return null;
    }
  }

和我的控制器

class ExploreController extends GetxController {
  var isLoading = true.obs;
  var articleList = <ExploreModel>[].obs;
  var offsetCount = 0;

  @override
  void onInit() {
    fetchArticles();
    super.onInit();
  }

  void fetchArticles({int offsetCount = 0}) async {
    try {
      isLoading(true);
      var articles = await ApiService.fetchArticleList(offsetCount);

      if (articles != null) {
        for (int i = 0; i < articles.length; i++) {
          articleList.addAll(articles[i]);
        }
      }
    } finally {
      isLoading(false);
    }
  }
}

这就是我想做的

Answer 1

改变这个：

List<ExploreModel> exploreModelFromJson(String str) => List<ExploreModel>.from(
    json.decode(str).map((x) => ExploreModel.fromJson(x)));

对此：

List<ExploreModel> exploreModelFromJson(String str) => List<ExploreModel>.from(
    json.decode(str).map((x) => ExploreModel.fromJson(x)).toList()); //add the toList().