es6类和"this"与事件处理程序 [英] es6 classes and "this" with event handlers

问题描述

玩一些es6，遇到了一个我不确定如何解决的问题.考虑以下

playing around with some es6 and ran into an issue i'm not sure how to solve. consider the following

class Foo {
 constructor ( ) {
   window.addEventListener('scroll', this.watch);
 }

 watch ( ) {
   console.log(this);
 }
}

在watch内，this是window对象，如预期的那样.但是，我怎么指代Foo?目前，我可以通过bind this.watch.bind(this)解决这个问题，但是我很想知道是否还有一种更合适的" ES6方法来实现这一目标.

Inside of watch, this is the window object, as expected. But how do i refer to Foo? Currently I get around this with bind this.watch.bind(this) but i'd love to know if there is a more "proper" ES6 way to get this going.

推荐答案

您可以使用箭头功能.

箭头函数表达式(也称为胖箭头函数) ) 有一个 与函数表达式相比语法更短，并且词法绑定 此值.

An arrow function expression (also known as fat arrow function) has a shorter syntax compared to function expressions and lexically binds the this value.

window.addEventListener('scroll', () => this.watch());

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