javascript 为什么 keydown 侦听器在 IE 中不起作用
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Why keydown listener doesn't work in IE
提问by Ixx
Im trying to run this in IE 8 but it doesn't work, any idea? It works in Firefox, Chrome, Opera...
我试图在 IE 8 中运行它，但它不起作用，知道吗？它适用于 Firefox、Chrome、Opera...
preventBackspace();
function preventBackspace() {
try {
if (window.addEventListener) {
window.addEventListener("keydown", onKeyDown, true);
} else if (window.attachEvent) { // IE
alert(window);
window.attachEvent("onkeydown", onKeyDown);
} else {
document.addEventListener("keydown", onKeyDown, true);
}
} catch (e) {
alert(e);
}
}
function onKeyDown(e) {
alert("test!");
}
jsfiddle:
jsfiddle：
window.attachEvent is defined and the event listener added. But it never shows "test!" alert.
window.attachEvent 已定义并添加了事件侦听器。但它从不显示“测试！” 警报。
I read something about useCapture flag, which is possible to use in the other methods. It captures the key press on the window before the event "goes down". Internet Explorer doesn't seem to allow/use this. Is that the problem? If yes, how can I solve it?
我读了一些关于 useCapture 标志的内容，它可以在其他方法中使用。它在事件“下降”之前捕获窗口上的按键。Internet Explorer 似乎不允许/使用它。这是问题吗？如果是，我该如何解决？
采纳答案by Snuffleupagus
Use document.attachEvent instead. :]
请改用 document.attachEvent。:]
回答by Jonathan Lonowski
It appears that only IE9 and later support binding keydownon window: http://www.quirksmode.org/dom/events/keys.html#t00
看来，只有IE9及更高版本支持绑定keydown上window：http://www.quirksmode.org/dom/events/keys.html#t00
Instead, bind it to the documentfor IE:
相反，将其绑定到documentfor IE：
function preventBackspace() {
try {
if (window.addEventListener) {
window.addEventListener("keydown", onKeyDown, true);
} else if (document.attachEvent) { // IE
alert(document);
document.attachEvent("onkeydown", onKeyDown);
} else {
document.addEventListener("keydown", onKeyDown, true);
}
} catch (e) {
alert(e);
}
}
