Flutter 获得；NoSuchMethodError：getter'；元素'；被调用为空。”；使用build_runner时

我是个新手，所以如果有人需要更多信息，请告诉我。 我一直在尝试将Hive与我的Flitter应用程序一起使用。我想为我编写的名为Product的类生成一个自定义适配器。当我运行“flatter包pub run build\u runner build”时，我得到的输出是：

NoSuchMethodError: The getter 'element' was called on null.
Receiver: null
Tried calling: element
[SEVERE] hive_generator:hive_generator on lib/Pages/Content Cards/productCard.dart:

NoSuchMethodError: The getter 'element' was called on null.
Receiver: null
Tried calling: element
[SEVERE] hive_generator:hive_generator on lib/Pages/Content Cards/featuredCard.dart:

NoSuchMethodError: The getter 'element' was called on null.
Receiver: null
Tried calling: element
[INFO] 19.8s elapsed, 5/14 actions completed.
[WARNING] hive_generator:hive_generator on lib/Models/product.dart:
Missing "part 'product.g.dart';".
[INFO] Running build completed, took 20.2s

[INFO] Caching finalized dependency graph...
[INFO] Caching finalized dependency graph completed, took 42ms

[SEVERE] Failed after 20.2s
pub finished with exit code 1

这是产品类别：

这是productCard.dart：

这是featuredCard.dart：

以下是我的pubsec.yaml的相关部分：

dependencies:
  flutter:
    sdk: flutter


  # The following adds the Cupertino Icons font to your application.
  # Use with the CupertinoIcons class for iOS style icons.
  cupertino_icons: ^0.1.3
  http: ^0.12.2
  hive: ^1.4.4
  hive_flutter: ^0.3.1
  # For OS-specific directory paths
  path_provider: ^1.6.18

dev_dependencies:
  build_runner:
  flutter_test:
    sdk: flutter
  hive_generator:

dependency_overrides:
  analyzer:

---

我尝试过修改build_runner和analyzer的版本，并在从中提取值之前检查产品对象是否为null。任何一个都无法正常工作。

错误消息显示您缺少“part”product.g.dart；”

我检查了你的代码，但没有找到。在

product.dart

中添加缺少的语句

import'package:hive/hive.dart'；
“产品g.省道”部分；
@HiveType（类型ID:1）
类产品{
///其他代码。。。
}

谢谢！它在添加行并再次运行命令后生成适配器。我需要担心getter'element'在空消息中被调用吗？很乐意提供帮助。你还收到那条消息吗？是的，只是空消息部分。当我调试时，这个应用程序似乎运行得很好。我在这里发现了一个类似的问题：你能检查一下它吗？我来看看。再次感谢你的帮助！