Freezed 是一个代码生成器，可帮助您在 Dart 中创建不可变、可序列化的类，减少重复代码，并提高代码可读性和可维护性。
Isar 是适用于 Flutter 的速度极快、易于使用且完全异步的 NoSQL 数据库。
Freezed 和 Isar 结合起来可让您：
- 使用 Freezed 类定义清晰且可维护的数据模型。
- 使用 Isar 轻松持久化数据。
- 执行高效的数据操作，例如获取、更新和删除。
添加依赖项
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isar_version: &isar_version 3.1.0+1 # define the isar version to be used
dependencies:
freezed_annotation: ^2.4.1
isar: *isar_version
isar_flutter_libs: *isar_version
dev_dependencies:
freezed: ^2.4.1
isar_generator: *isar_version
build_runner: any
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定义 Class
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import 'package:freezed_annotation/freezed_annotation.dart';
import 'package:isar/isar.dart';
part 'message.freezed.dart';
part 'message.g.dart';
const modelFreezed = Freezed();
const isarCollection = Collection(ignore: {'props', 'copyWith'});
@modelFreezed
@isarCollection
class Message with _$Message {
const Message._();
const factory Message({
@Index(unique: true) required String id,
required String text,
@Default(MessageStatus.success) MessageStatus status,
// ...
}) = _Message;
Id get isarId => fastHash(id);
@override
@enumerated
MessageStatus get status => super.status;
factory Message.fromJson(Map<String, dynamic> json) =>
_$MessageFromJson(json);
}
enum MessageStatus {
success,
cancel,
timeout,
error;
bool get isSuccess => this == success;
bool get isCancel => this == cancel;
bool get isTimeout => this == timeout;
bool get isError => this == error;
}
/// FNV-1a 64bit hash algorithm optimized for Dart Strings
int fastHash(String string) {
var hash = 0xcbf29ce484222325;
var i = 0;
while (i < string.length) {
final codeUnit = string.codeUnitAt(i++);
hash ^= codeUnit >> 8;
hash *= 0x100000001b3;
hash ^= codeUnit & 0xFF;
hash *= 0x100000001b3;
}
return hash;
}
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生成代码
运行以下命令来生成代码：
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flutter pub run build_runner build --delete-conflicting-outputs
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享受编码吧 🎉
