从onSubmit事件处理程序添加或减去函数？

问题描述

我有以下代码：

function showAddrBox() {
    var prompt = document.getElementById('addr_prompt');
    prompt.style.display = 'block';
    document.generic_form.address.style.display = 'block';
    document.generic_form.onsubmit = validateAddrForm;
}

function hideAddrBox() {
    var prompt = document.getElementById('addr_prompt');
    prompt.style.display = 'none';
    document.generic_form.address.style.display = 'none';
    document.generic_form.onsubmit = null;
}

问题是我有时会在onSubmit附加我想要的附加功能保留。我希望能够在onSubmit事件中添加和删除单个函数，而不只是使用onsubmit =设置它们。换句话说，我需要一种方法来完成这样的事情：

The problem is that sometimes I have additional functions attached to onSubmit that I want to preserve. I want to be able to add and remove individual functions from the onSubmit event, not just set them with "onsubmit =". In other words, I need a way to accomplish something like this:

document.form.onsubmit += function;
document.form.onsubmit -= function;

任何想法？

推荐答案

使用 element.addEventListener（eventName，callbackFunction，false）和 element.removeEventListener（eventName，callbackFunction） 。

其中eventName是没有'on'的处理程序的名称。所以onsubmit变成提交。

Where eventName is the name of the handler without the 'on'. So onsubmit becomes submit.

有关这两个函数的文档，请参阅：

For documentation of the two functions, see:

• https://developer.mozilla.org/en/DOM/element.addEventListener
• https://developer.mozilla.org/en/DOM/element.removeEventListener

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