addEventListener函数不适用于“ onkeyup”事件

Question

JavaScript

window.onload = initialise;

use = document.getElementById("use");

function initialise() {
    username = document.getElementById('username');
    username.addEventListener('onkeydown', respond, false);
}

function respond() {
    alert();
    //if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
    //    use.innerHTML=xmlhttp.responseText;
}

The username variable here is an input text field in another HTML document, looking like this:

<input type="text" name="username" id="username">

This is not working; how can I make it work?

Answer 1

使用keydown代替Onkeydown 。

Answer 2

When using addEventListener you omit the "on" prefix in the event name

addEventListener('keydown', , /**/,/**/);
addEventListener('click', , /**/,/**/);
addEventListener('mouseover', , /**/,/**/);
//etc

instead of

addEventListener('onkeydown', , /**/,/**/);
addEventListener('onclick', , /**/,/**/);
addEventListener('onmouseover', , /**/,/**/);
//etc

Spec for event list types

However if supporting older IE browsers you will need attachEvent which uses "on" prefix