问题描述
很抱歉，如果这是一个常见问题，但我找不到通过搜索找到的相关答案。
Sorry if this is a common question, but I couldn't find any answers that seemed pertinent through searching.
如果我附加了这样的事件侦听器，则： / p>
If I attach an event listener like this:
window.addEventListener('scroll', function() { check_pos(box); }, false);
稍后尝试删除它似乎不起作用，像这样：
it doesn't seem to work to try to remove it later, like this:
window.removeEventListener('scroll', function() { check_pos(box); }, false);
我认为这是因为 addEventListener 和 removeEventListener 方法想要引用相同的函数，而我为它们提供了匿名函数，尽管它们在代码上相同，但实际上并不相同。
I assume this is because the addEventListener and removeEventListener methods want a reference to the same function, while I've provided them with anonymous functions, which, while identical in code, are not literally the same.
如何更改代码以使对 removeEventListener 的调用正常工作？ box参数是指我在屏幕上跟踪的< iframe> 的名称；也就是说，我希望能够为每个拥有的< iframe> 预订一次 scroll 事件（数量会有所不同），一旦 check_pos（）函数测量到某个位置后，它将调用另一个函数，并删除事件侦听器以释放系统资源。
How can I change my code to get the call to removeEventListener to work? The "box" argument refers to the name of an <iframe> that I'm tracking on the screen; that is, I want to be able to subscribe to the scroll event once for each <iframe> that I have (the quantity varies), and once the check_pos() function measures a certain position, it will call another function and also remove the event listener to free up system resources.
我的直觉是该解决方案将涉及到闭包和/或命名匿名函数，但我不确定到底是什么样，并希望举一个具体的例子。
My hunch is that the solution will involve a closure and/or naming the anonymous function, but I'm not sure exactly what that looks like, and would appreciate a concrete example.
希望如此。
推荐答案
您是否尝试过维护对匿名函数的引用（如您建议的那样）？
Have you tried maintaining a reference to the anonymous function (like you suggested)?
所以：
var listener = function() {
check_pos(box);
};
window.addEventListener('scroll', listener, false);
...
window.removeEventListener('scroll', listener, false);
Mozilla的文档同一件事。
Mozilla's docs suggest the same thing.
这篇关于如何使用带有参数的函数添加和删除事件侦听器？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！