使用JavaScript触发带有数据的键盘事件

Triggering Keyboard events with data using JavaScript

本文关键字：数据 键盘 事件 JavaScript 使用      更新时间：2023-09-26

这似乎是一个重复的问题。但是我搜索了很多地方，我无法找到使用纯javascript(不使用jQuery)发送事件数据的适当示例。

https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent没有任何例子

我需要这样的东西。https://developer.mozilla.org/en-US/docs/Web/Guide/Events/Creating_and_triggering_events Adding_custom_data_.E2.80.93_CustomEvent

的例子:

// listening for keypress event,    
ele.addEventListener("keydown", function(e){
    console.log(e.keyCode); //expecting 50
});

// triggering like this
var e = new KeyboardEvent("keydown", {keyCode: 50});
ele.dispatchEvent(e);

在Axel Rauschmayer博士的帖子http://www.2ality.com/2013/06/triggering-events.html的帮助下

你可以使用以下3个构造函数来触发，

// use any one of these constructor as per your usecase
var e = new Event("keydown"); //without any data
var e = new CustomEvent("keydown", {detail: {prop1: "value"}}); //if any data required use detail: only detail/bubbles/cancelable properties can be passed here
var e = new KeyboardEvent("keydown");
// add properties
e.keyCode = 50; // works for *Event* and *CustomEvent* constructors
e.key = 50; // in *KeyboardEvent* constructor *keyCode* is **readonly** property so use *key* property. Refer properties detail using https://developer.mozilla.org/en-US/docs/Web/Reference/Events/keydown
e.anyNewProp = "value"; // if any new prop is required
// finally dispatchEvent using dispatchEvent method of dom element
ele.dispatchEvent(e);

// listening for keypress event,    
ele.addEventListener("keydown", function(e){
    console.log(e.keyCode); //results 50
    console.log(e.key); //results 50
    console.log(e.anyNewProp); //results "value"
});

使用本地KeyboardEvent构造函数是最有意义的。然而，@Darshan的例子在2022年更新的浏览器上不再工作，因为事件的属性是只读的(developer.mozilla.org)，相反，你必须将一个初始化字典传递给构造函数:

// ! Note that KeyboardEvent.keyCode are deprecated as of 2022
const keyPressCode50 = new KeyboardEvent('keypress', {keyCode: 50});
element.dispatch(keyPressCode50);
// Equivalently, you can initialize the `key` or depending on the where its used, multiple properties.
const keyPressKey2   = new KeyboardEvent('keypress', {key: '2', code: 'Digit2'};
element.dispatch(keyPressKey2);
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