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发布订阅模式（也称观察者模式）是一种管理跨组件通信的有效方式，尤其是在不希望直接依赖于特定组件的情况下。这种模式允许一个对象（发布者）通知多个其他对象（订阅者），而不必知道这些对象是谁或他们在哪里。这有助于解耦组件，使得代码更加模块化和可维护。

1.创建发布订阅器

创建一个发布订阅器类，负责管理时间的注册、取消和触发

# js
class PubSub {constructor(){this.events = {}}subscribe(event, callback){if(!this.events[event]){this.events[event] = []}this.events[event].push(callback)}unsubscribe(event,callback){if(this.events[event]){this.events[event] = this.events[event].filter(cb => cb !== callback)}}publish(event,data){if(this.events[event]){this.events[event].forEach(callback => callback(data))}}
}const pubsub = new PubSub()

# tsinterface EventMap {[eventName: string]: any;
}class EventCenter {private listeners = {}constructor(){this.listeners = {}}subscribe<T extends keyof EventMap>(event: T, callback: (data?: EventMap[T]) => void) {if(!this.listeners[event]) {this.listeners[event] = []}this.listeners[event].push(callback)}publish<T extends keyof EventMap>(event: T, data?: EventMap[T]) {const callbacks = this.listeners[event]if(callbacks) {callbacks.forEach(callback => {callback(data)})}}unsubscribe<T extends keyof EventMap>(event: T, callback?: (data: EventMap[T]) => void) {const callbacks = this.listeners[event];if (callbacks) {if (callback) {this.listeners[event] = callbacks.filter(cb => cb !== callback);} else {delete this.listeners[event];}}}
}export default new EventCenter()

2.在组件中使用发布订阅器

在你的React组件中使用这个发布订阅器。例如，一个组件可以订阅事件以接收数据，而另一个组件可以发布事件来发送数据。假设你有一个按钮组件，当点击时，他会触发一个事件发送一些数据

import React from 'react';
import { pubsub } from './pubsub'; // 引入上面定义的PubSub实例class ButtonComponent extends React.Component {handleClick = () => {pubsub.publish('dataUpdated', { message: 'Hello World!' });};render() {return (<button onClick={this.handleClick}>Click me!</button>);}
}

3. 订阅数据

另一个组件可以订阅这个事件，并在接收到数据时执行某些操作

import React, { useEffect, useState } from 'react';
import { pubsub } from './pubsub'; // 引入上面定义的PubSub实例interface DisplayProps {}
interface DisplayState {message: string;
}const DisplayComponent: React.FC<DisplayProps> = () => {const [message, setMessage] = useState('');useEffect(() => {const handleDataUpdate = ({ message }: { message: string }) => {setMessage(message);};pubsub.subscribe('dataUpdated', handleDataUpdate);return () => {pubsub.unsubscribe('dataUpdated', handleDataUpdate);};}, []);return <div>{message}</div>;
};export default DisplayComponent;