调用API的异步列表类型后，文件列表变量类型重置

Question

我将文件列表传递给函数。调用DB后，文件变量列表重置。API返回类型是List。而且没有办法从另一种方式重新设置attachFiles。

这是我的函数

   List<File> attachFiles = [];

  Future postRequest(BuildContext context, PostModel postModel) async {
    List<RequirementModel> requirements = [];
    attachFiles = postModel.fileNotifierValues;
    print('attach files-1 : ${attachFiles?.length}');
    requirements = List.from(await db.checkRequirement(postModel.customerId, postModel.subCategory.subCategoryId));
    print('attach files-2 : ${attachFiles?.length}');
...
}

输出结果

attach files-1 : 1
attach files-2 : 0

checkRequirement函数

  Future<List<RequirementModel>> checkRequirement(String uid, String subId) async {
    var ref = _db
        .collection('requirement')
        .where('status', isEqualTo: 'Active')
        .where('customerId', isEqualTo: uid)
        .where('subCategory.id', isEqualTo: subId);

    List<RequirementModel> model = await ref.get().then((list) => list.docs.map((doc) => RequirementModel.fromForestore(doc)).toList());
    if ((model?.length ?? 0) != 0) {
      model.removeWhere((element) => element.enquiryPrivate == true);
      model.removeWhere((element) => element.isPromoInquiry == true);
      return model;
    } else {
      return [];
    }
  }

颤振医生-v

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Answer 1

这是达特语言的问题。我把我的代码改成这个。现在一切都好了。

从…

attachFiles = postModel.fileNotifierValue;

到这个

attachFiles = List.from(postModel.fileNotifierValue ?? []);