在js中使用事件构造函数的一个很好的例子是什么？ [英] What is a good example of using event constructors in js?

问题描述

https://developer.mozilla.org/en-US/docs/DOM/document.createEvent

最上方告诉我以下内容：

不建议使用createEvent方法。使用事件构造函数代替。

Googling JS事件构造函数不是很有成果 - 主题谈论一般的构造函数，但不是我正在查找对于。有人可以向我解释什么是事件构造函数，并提供一个很好的例子？

解决方案

从https://developer.mozilla.org/en-US/docs/Web/API/CustomEvent ：

似乎事件现在封装在一个名为CustomEvent的类中。您可以将旧的document.createEvent视为返回事件对象的工厂方法。现在，而不是使用document.createEvent创建对象，现在可以直接创建对象。

  // this是新的方式
 var my_event = new CustomEvent（'NewEventName'）; 
 var my_element = document.getElementById（'TargetElement'）; 
 my_element.dispatchEvent（my_event）; 
  

代替

  //这是旧的方式
 var my_event = document.createEvent（'NewEventName'）; 
 var my_element = document.getElementById（'TargetElement'）; 
 my_element.dispatchEvent（my_event）; 
  

I am trying to figure out how to properly create and fire events in JavaScript, so in the process of learning ran into this page:

https://developer.mozilla.org/en-US/docs/DOM/document.createEvent

Which at the top informs me of the following:

The createEvent method is deprecated. Use event constructors instead.

Googling JS event constructors was not very fruitful - topics talking about constructors in general, but not what I am looking for. Could somebody please explain to me what are the event constructors and provide a good example of their usage?

解决方案

From https://developer.mozilla.org/en-US/docs/Web/API/CustomEvent:

It seems that events are now encapsulated in a class called CustomEvent. You can think of the old document.createEvent as a factory method that returns an event object. Now, instead of using document.createEvent to create the object, you now have access to create the object directly.

    //this is the new way
    var my_event = new CustomEvent('NewEventName');
    var my_element = document.getElementById('TargetElement');
    my_element.dispatchEvent(my_event);

is the replacement for

    //this is the old way
    var my_event = document.createEvent('NewEventName');
    var my_element = document.getElementById('TargetElement');
    my_element.dispatchEvent(my_event);

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