我已经添加了按键监听器,这是行不通的。
当调用“ click”的侦听器时-工作正常。
这是代码:
var closeSave = document.getElementById("closeSave");
closeSave.addEventListener("click", closeWindow);
closeSave.addEventListener("keypress", closeWindowByEsc);
// When the user clicks on <span> (x), close the modal
var closeWindow = function() {
saveModal.style.display = "none";
loadModal.style.display = "none";
}
var closeWindowByEsc = function(){
if (!e) e = window.event;
var keyCode = e.keyCode || e.which;
if (keyCode == '27'){
closeWindow(e);
}
}
可能是什么问题呢?
最佳答案
问题在于,声明var func = function () { ...
将var func;
部分提升到范围的顶部,但是func
在到达该行之前才被定义为function () { ...
。因此,当您附加事件处理程序时,本质上就是这样:
var closeSave = document.getElementById("closeSave");
var closeWindow;
var closeWindowByEsc;
// here, closeWindow and closeWindowByEsc are `undefined`
closeSave.addEventListener("click", closeWindow);
closeSave.addEventListener("keypress", closeWindowByEsc);
// When the user clicks on <span> (x), close the modal
closeWindow = function() {
saveModal.style.display = "none";
loadModal.style.display = "none";
}
closeWindowByEsc = function(e) {
if (!e) e = window.event;
var keyCode = e.keyCode || e.which;
if (keyCode == '27') {
closeWindow();
}
}
您可以做两件事来解决此问题:
将
addEventListener()
移到实例化下面:var closeSave = document.getElementById("closeSave");
// When the user clicks on <span> (x), close the modal
var closeWindow = function() {
saveModal.style.display = "none";
loadModal.style.display = "none";
}
var closeWindowByEsc = function(e) {
if (!e) e = window.event;
var keyCode = e.keyCode || e.which;
if (keyCode == '27') {
closeWindow();
}
}
closeSave.addEventListener("click", closeWindow);
closeSave.addEventListener("keypress", closeWindowByEsc);
或者,您可以使用将实例化提升到作用域顶部的函数语句,而不是函数表达式:
var closeSave = document.getElementById("closeSave");
closeSave.addEventListener("click", closeWindow);
closeSave.addEventListener("keypress", closeWindowByEsc);
// When the user clicks on <span> (x), close the modal
function closeWindow() {
saveModal.style.display = "none";
loadModal.style.display = "none";
}
function closeWindowByEsc(e) {
if (!e) e = window.event;
var keyCode = e.keyCode || e.which;
if (keyCode == '27') {
closeWindow();
}
}
关于javascript - Esc事件监听器不起作用,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/44857419/