Javascript从事件处理程序中获取对父对象/类的引用 [英] Javascript get reference to parent object/class from event handler

问题描述

我有一个类（或包含函数的对象;我听说没有像JavaScript类一样的东西），名为Foo，带有附加到点击事件的事件处理程序。当调用事件处理程序时，我想修改我的类Foo的属性。通常，我将使用 this 关键字，但在事件处理程序中， this 引用设置为引用html元素。这是我的代码：

  function Foo（）{
 
 this.num = 0; 
 $（'element'）。click（this.eventHandler）; // jQuery将onclick事件附加到我的元素。 
 
 this.eventHandler = function（）{
 this.num ++; //这不工作。 
 //通常，this指的是我的Foo实例，
 //但是作为事件处理程序，this指的是html元素。 
} 
} 
  

所以我的问题是：我的实例Foo进入我的事件处理程序，以便我可以修改其属性（如 num ）？

  function Foo（）{
 var _self = this; 
 this.num = 0; 
 
 $（'element'）。click（this.eventHandler）; // jQuery将onclick事件附加到我的元素。 
 
 this.eventHandler = function（）{
 _self.num ++; 
} 
} 
  

使用引用 _self =此在外部范围

中定义

I have a class (or function-containing object; I've heard that there is no such thing as a Javascript class) called Foo, with an event handler that is attached to a click event. When the event handler is called, I want to modify a property of my class Foo. Normally, I would use the this keyword, but in the event handler, the this reference is set to the reference to the html element. Here is my code:

function Foo() {

    this.num=0;
    $('element').click(this.eventHandler);// jQuery to attach an onclick event to my element.

    this.eventHandler=function() {
        this.num++;// This doesn't work.
        // Normally, "this" would refer to my instance of Foo,
        // but as an event handler, "this" refers to the html element.
    }
}

So my question is: how do I get a reference to my instance of Foo into my event handler so that I can modify its properties (like num)?

解决方案

function Foo() {
    var _self = this;
    this.num=0;

    $('element').click(this.eventHandler);// jQuery to attach an onclick event to my element.

    this.eventHandler=function() {
        _self.num++;
    }
}

use a reference _self = this defined in the outer scope

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