use_enums

Use enums rather than classes that behave like enums.

此规则自 Dart 2.17 版本起可用。

此规则提供 快速修复 。

Classes that look like enumerations should be declared as enums.

DO use enums where appropriate.

Candidates for enums are classes that:

• are concrete,
• are private or have only private generative constructors,
• have two or more static const fields with the same type as the class,
• have generative constructors that are only invoked at the top-level of the initialization expression of these static fields,
• do not define hashCode, ==, values or index,
• do not extend any class other than Object, and
• have no subclasses declared in the defining library.

To learn more about creating and using these enums, check out Declaring enhanced enums.

BAD:

class LogPriority {
  static const error = LogPriority._(1, 'Error');
  static const warning = LogPriority._(2, 'Warning');
  static const log = LogPriority._unknown('Log');

  final String prefix;
  final int priority;
  const LogPriority._(this.priority, this.prefix);
  const LogPriority._unknown(String prefix) : this._(-1, prefix);
}

GOOD:

enum LogPriority {
  error(1, 'Error'),
  warning(2, 'Warning'),
  log.unknown('Log');

  final String prefix;
  final int priority;
  const LogPriority(this.priority, this.prefix);
  const LogPriority.unknown(String prefix) : this(-1, prefix);
}

要启用 use_enums 规则，请在你的 analysis_options.yaml 文件中，在 linter > rules 下添加 use_enums ：

linter:
  rules:
    - use_enums

除非另有说明，否则本网站上的文档反映的是 Dart 3.6.0。页面最后更新于 2025-02-05。 查看源代码 或 报告问题.