flutter ：需要冻结或用 @Default 标记

Question

我正在尝试在我的应用程序上使用冻结，所以我添加了

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environment:\n  sdk: ">=2.7.0<3.0.0"\n\n  freezed: ^0.14.0\n  freezed_annotation: ^0.14.0\n

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到我的依赖。

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dev_dependencies:\n  freezed_annotation: ^0.12.0\n  build_runner:  ^2.0.1\n  retrofit_generator:\n  flutter_localizations:\n    sdk: flutter\n  flutter_test:\n    sdk: flutter\n

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之后我创建简单的冻结类：

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import 'package:freezed_annotation/freezed_annotation.dart';\n\npart 'chart_daily_expanded_detailes_model.freezed.dart';\n\n@freezed\nabstract class ChartDailyExpandedDetailesModel\n    with _$ChartDailyExpandedDetailesModel {\n  const factory ChartDailyExpandedDetailesModel({\n    String title,\n    String testNumber,\n    String testPercentage,\n    String icon,\n  }) = _ChartDailyExpandedDetailesModel;\n}\n

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但我收到了这个错误：

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[SEVERE] freezed:freezed on lib/new_develop/model/test/chart_daily_expanded_detailes_model.dart:\n\nThe parameter `title` of `ChartDailyExpandedDetailesModel` is non-nullable but is neither required nor marked with @Default\npackage:app/new_develop/model/test/chart_daily_expanded_detailes_model.dart:9:12\n  \xe2\x95\xb7\n9 \xe2\x94\x82     String title,\n

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这是颤振医生：

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Doctor summary (to see all details, run flutter doctor -v):\n[\xe2\x9c\x93] Flutter (Channel stable, 2.2.3, on Linux, locale en_US.UTF-8)\n[!] Android toolchain - develop for Android devices (Android SDK version 30.0.3)\n    \xe2\x9c\x97 Android license status unknown.\n      Run `flutter doctor --android-licenses` to accept the SDK licenses.\n      See https://flutter.dev/docs/get-started/install/linux#android-setup for more details.\n[\xe2\x9c\x93] Chrome - develop for the web\n[\xe2\x9c\x93] Android Studio (version 4.2)\n[\xe2\x9c\x93] Android Studio\n[\xe2\x9c\x93] VS Code (version 1.60.0)\n[\xe2\x9c\x93] Connected device (2 available)\n\n! Doctor found issues in 1 category.\n

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我的项目不是空安全的，我想在非空安全状态下使用冻结。

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Answer 1

在项目之前添加required，或者您可以使用它使其可为空String?或提供默认值，例如 @Default("") String icon,

@freezed
abstract class ChartDailyExpandedDetailesModel
    with _$ChartDailyExpandedDetailesModel {
  const factory ChartDailyExpandedDetailesModel({
    required String title,
    required String testNumber,
     String? testPercentage, //nullable item
    @Default("") String icon, //contain default value
  }) = _ChartDailyExpandedDetailesModel;
}