轻松学 Node.js - 基础篇免费视频教程 #5 事件

最好用 ES6 哈哈哈

实践课会用 es6

let events = require('events');
let utils = require('util');

// let myEmitter = new events.EventEmitter();

// myEmitter.on('connected',(message)=>{
// console.log(message);
// })
//按监听器的注册顺序，同步地调用每个注册到名为 eventName 事件的监听器，并传入提供的参数。
// myEmitter.emit('connected','你好世界')

class Person extends events.EventEmitter {
constructor(name){
super();
this.name = name;
}
}
let lily = new Person('Lily');
let lucy = new Person('Lucy');

let peoples = [lily, lucy];
peoples.forEach(people => {
people.on('say',(message)=>{
console.log(message,this);
})
});
lily.emit('say','你好啊,世界');
lucy.emit('say','欢迎,大千世界')

const EventEmitter = require('events');
class MyEmitter extends EventEmitter {}

const fun1= new MyEmitter();
const fun2= new MyEmitter();
const fun3= new MyEmitter();

let arr = [fun1,fun2,fun3];
arr.forEach((item)=>{
item.on('event', msg => {
console.log(msg);
});
})
fun1.emit('event','fun1');
fun2.emit('event','fun2');
fun3.emit('event','fun3');

这章我基本上看得一头雾水~

讲的很棒

const EventEmitter = require('events');

class Person extends EventEmitter {
constructor(name) {
super();
this.name = name;
}
}

let xiaoming = new Person('xiaoming');
let lili = new Person('lili');
let lucy = new Person('lucy');

let person = [xiaoming, lili, lucy];

person.forEach(function(person) {
person.on('speak', function(message) {
console.log(person.name + "say" + message);
})
});

xiaoming.emit('speak', 'hi');

var events = require('events');
// util 是一个 node 核心工具库，包含很多功能
var util = require('util');

var Person = function(name) { // 定义一个 Person 类
this.name = name
}

// Person 继承于 events.EventEmitter
util.inherits(Person, events.EventEmitter);

// 新建三个对象
var xiaoming = new Person('xiaoming');
var lili = new Person('lili');
var lucy = new Person('lucy');

var person = [xiaoming, lili, lucy];

person.forEach(function(person) {
// 给每个人绑定一个事件
person.on('speak', function(message) {
console.log(person.name + " said: " + message);
})
})

// 触发事件：
xiaoming.emit('speak', 'hi');
lucy.emit('speak', 'I want a curry');

//nodejs中的一个工具库
const util = require('util');
//nodejs中的一个事件库
const events = require('events');
var someEvent=new events.EventEmitter();

someEvent.on('someEvent',function(name){
    console.log(name);
})
someEvent.emit("someEvent","代码运行自动触发事件");


//Person继承事件功能(采用的是Es6的写法)
class Person extends events{

    //定义的一个方法
    writeName(data,name) {
        //this这里可以理解为就是Person对象
        this.emit('click', data+"   "+name);
    }
    //foreach中调用的
    everyPersonName(name) {
        this.emit('click',name);
    }
    //名字的set和get方法
    setName(name){
        this.name=name;
    }
    getName(){
        return this.name;
    }

}
const personOne=new Person();
personOne.setName("zhangsan");
const personTwo=new Person();
personTwo.setName("lisi");

var persons=[personOne,personTwo];
persons.forEach(function(person){
    person.on('click',function(data){
        console.log(person.getName()+"  hi hi");
    })
})
personOne.everyPersonName(personOne.getName())
personTwo.everyPersonName(personTwo.getName())

const myPerson=new Person();
//因为person这个对象继承的是events所以有on事件
//Es6语法,箭头函数(data)=>{}
myPerson.on('click', (data) => {
    console.log(`${data}`);
});
//传统语法function(){}
myPerson.on('click',function(data){
    console.log(data);
});
myPerson.writeName("采用的是Es6的语法形式","zhangsan");

结果:
代码运行自动触发事件
zhangsan hi hi
lisi hi hi
采用的是 Es6 的语法形式 zhangsan
采用的是 Es6 的语法形式 zhangsan