NodeJS Events 模块笔记

1. 环境 node 8.11.3 2. 基本使用 // 01.js const EventEmitter = require('events'); class MyEmitter extends EventEmitter {} const myEmitter = new MyEmitter(); myEmitter.on('event', () => { console.log('an event occurred!'); }); myEmitter.emit('event'); 输出: an event occurred! 3. 传参与this指向 emit()方法可以传不限制数量的参数。 除了箭头函数外,在回调函数内部,this会被绑定到EventEmitter类的实例上 // 02.js const EventEmitter = require('events') class MyEmitter extends EventEmitter {} const myEmitter = new MyEmitter() myEmitter.on('event', function (a, b){ console.log(a, b, this, this === myEmitter) }) myEmitter....

2018-08-10 · 2 min · 王端端