你好，我在这里提出我的方法，它以某种方式工作，以避免在DOM的同一元素上进行多个侦听。我的方法使用JQUERY，但原理如下:

在对应用程序进行特定处理(必须在DOM元素(如click)上重新生成侦听器)之后，我们首先删除该事件以避免多次出现该事件，然后立即重新创建它。

这一原则要根据需要加以调整。这只是原理。我向你展示如何在jquery。

line 1 : $(_ELTDOM_).unbind('click');
line 2 : $(_ELTDOM_).bind('click',myFct);

我希望通过调整这个解决方案可以帮助到一些人。我坚持认为，这种解决方案不一定适用于所有情况，但它已经使解决与双、三重……相关的问题成为可能。例如，由于同一元素上的多个侦听而导致的同时处理

没有办法检查动态附加的事件侦听器是否存在。

查看事件监听器是否被附加的唯一方法是像这样附加事件监听器:

elem.onclick = function () { console.log (1) }

然后，您可以通过返回!!elem测试事件侦听器是否附加到onclick。点击(或类似的东西)。

我要做的是在你的函数外面创建一个布尔值，开始时为FALSE，当你附加事件时被设置为TRUE。在再次附加事件之前，这将作为某种标志。这里有一个关于这个想法的例子。

// initial load
var attached = false;

// this will only execute code once
doSomething = function()
{
 if (!attached)
 {
  attached = true;
  //code
 }
} 

//attach your function with change event
window.onload = function()
{
 var txtbox = document.getElementById('textboxID');

 if (window.addEventListener)
 {
  txtbox.addEventListener('change', doSomething, false);
 }
 else if(window.attachEvent)
 {
  txtbox.attachEvent('onchange', doSomething);
 }
}

我写了3个函数来做这个:

var addEvent = function(object, type, callback)
{
    if (object != null && typeof(object) != 'undefined' && object.addEventListener)
    {
        object.isAttached = typeof object.isAttached == "undefined" ? [] : object.isAttached;
        if (!object.isAttached[type])
        {
            object.isAttached[type] = true;
            object.addEventListener(type, callback, false);
        }
    }
};

var removeEvent = function(object, type, callback)
{
    if (object != null && typeof(object) != "undefined" && typeof object.isAttached != "undefined" && object.isAttached[type])
    {
        object.removeEventListener(type, callback, false);
        object.isAttached[type] = false;
    }
};

var hasEvent = function(object, type, callback)
{
    return object != null && typeof(object) != "undefined" && typeof object.isAttached != "undefined" && object.isAttached[type];
};

函数的使用很简单:

function mousemove(e)
{
    console.log("x:" + e.clientX + ", y:" + e.clientY);
}

if (hasEvent(window, "mousemove", mousemove))
    console.log('window has "mousemove" event with "mousemove" callback');
else
    console.log('window does not have "mousemove" event with "mousemove" callback');

addEvent(window, "mousemove", mousemove);

if (hasEvent(window, "mousemove", mousemove))
    console.log('window has "mousemove" event with "mousemove" callback');
else
    console.log('window does not have "mousemove" event with "mousemove" callback');
/*
Output
window does not have "mousemove" event with "mousemove"
window has "mousemove" event with "mousemove" callback
The x and y coordinates of mouse as you move it
*/

//在匿名函数的外部赋值

const element = document.getElementById('div');
if (element && !element.hasAttribute('listenerOnClick')) {
    element.addEventListener('click', function () {
        const elementClicked = this;
        // fnDoAnything(this); // maybe call a function with the elementClicked...
        console.log('event has been attached');
    });
}
element.setAttribute('listenerOnClick', 'true');

var listenerPaste = pasteAreaElm.hasOwnProperty('listenerPaste');
if (!listenerPaste) {
    pasteAreaElm.addEventListener("paste", onPasteEvent, false);
    pasteAreaElm.listenerPaste = true;
}