在Dart中移植JS地圖

Question

如何在dart中移植此const？

const CHANNEL_STATES = {
  closed: "closed",
  errored: "errored",
  joined: "joined",
  joining: "joining",
  leaving: "leaving",
}

我需要打電話給ex。 CHANNEL_STATES.closed謝謝

Answer 1

您可以使用類和常量靜態成員來執行此操作：

class CHANNEL_STATES {
  static const String closed = "closed";
  static const String errored = "errored";
  static const String joined = "joined";
  static const String joining = "joining";
  static const String leaving = "leaving";
}

Answer 2

我不確定您要的是什么，但是Dart中類似的地圖常量將是：

const channelStates = const {
  "closed": "closed",
  "errored": "errored",
  "joined": "joined",
  "joining": "joining",
  "leaving": "leaving",
};

Dart映射文字可以使用任何對象作為鍵，因此要使用字符串作為鍵，您需要將其引號。 您不能僅使用JavaScript中未加引號的標識符。