当对象由类组成时访问对象属性

Question

对象包含对类的引用：

// commands/index.ts
export default {
  Authorize,
  BootNotification,
  ...
  UpdateFirmware,
};

我如何着手创建变量并从此对象动态实例化？对于类似下面的内容，我收到 ts 错误：

TS2538: Type '{ Authorize: typeof Authorize; BootNotification: typeof BootNotification; CancelReservation: typeof CancelReservation; ChangeAvailability: typeof ChangeAvailability; ... 23 more ...; UpdateFirmware: typeof UpdateFirmware; }' cannot be used as an index type.

代码：

import commands from "./commands"; 
let commandNameOrPayload: typeof commands;
let commandPayload: any;
let CommandModel: typeof commands;

CommandModel = commands[commandNameOrPayload];
commandRequest = new CommandModel(commandPayload);

对于 newCommandModel 的最后一行，我收到错误：TS2351: This expression is not constructable.

Answer 1

您的 commands 导出的类由其名称的字符串表示索引，因此为了访问它们，您的 commandNameOrPayload 也需要是类型 string:

class A {/**bla**/}

class B {/**bla**/}

let commands = {
  A,
  B
}

console.log(commands["A"]) // will log class A {}
let command = new commands["A"];

console.log(command instanceof A)

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当对象由 类 组成时访问对象 属性

Accessing object property when object consists of classes

types

typescript

当对象由类组成时访问对象属性