我无法在课堂上正确访问此属性

Question

为什么我无法在我的运行函数中访问this.name 属性？

基本事件类：

import { ClientEvents } from 'discord.js';

import DiscordClient from './DiscordClient';

export default abstract class Event {
    readonly client: DiscordClient;
    readonly name: keyof ClientEvents | "raw";

    constructor(client: DiscordClient, name: keyof ClientEvents | "raw") {
        this.client = client;
        this.name = name;
    }

    /**
     * Runs the event.
     * @param params Parameters
     */
    abstract run(...params: any | undefined): Promise<void>;
}

示例事件类：

import DiscordClient from '../structures/DiscordClient';
import Event from '../structures/Event';

export default class ReadyEvent extends Event {

    constructor(client: DiscordClient) {
        super(client, "ready");
        console.log(this.name); // Output: ready
    }

    async run() {
        console.log(this.name); // Output: undefined
    }

}

我正在注册这样的事件：(this.clientinstanceof DiscordClient)

/**
 * Registers single event.
 * @param event Event
 */
private registerEvent(event: any) {
    if (isConstructor(event, Event)) event = new event(this.client);
    else if (isConstructor(event.default, Event)) event = new event.default(this.client);
    if (!(event instanceof Event)) throw new Error(`Invalid event object to register: ${event}`);

    const evt = event as Event;

    if (this.events.some(e => e.name === evt.name)) throw new Error(`A event with the name "${evt.name}" is already registered.`);

    this.events.set(evt.name, evt);
    this.client.on(evt.name as keyof ClientEvents, evt.run);
}

Answer 1

将evt.run 更改为evt.run.bind(evt)，以便使用正确的this 调用函数。

另见How does the "this" keyword work?"