如何检查click事件是否已绑定-JQuery [英] How to check if click event is already bound - JQuery

问题描述

我将点击事件与按钮绑定在一起:

I am binding a click event with a button:

$('#myButton').bind('click',  onButtonClicked);

在一种情况下，该调用被多次调用，所以当我执行trigger时，我看到了多个我想防止的ajax调用.

In one scenario, this is getting called multiple times, so when I do a trigger I see multiple ajax calls which I want to prevent.

只有在未绑定bind的情况下，才应如何操作.

How do I bind only if its not bound before.

推荐答案

2012年8月24日更新:在jQuery 1.8中，不再可以使用.data('events')访问元素的事件. (有关详细信息，请参见此错误.)可以使用jQuery._data(elem, 'events')访问相同的数据，内部数据结构，未记录，因此不能保证100％保持稳定.但是，这应该不成问题，并且上面插件代码的相关行可以更改为以下内容:

Update 24 Aug '12: In jQuery 1.8, it is no longer possible to access the element's events using .data('events'). (See this bug for details.) It is possible to access the same data with jQuery._data(elem, 'events'), an internal data structure, which is undocumented and therefore not 100% guaranteed to remain stable. This shouldn't, however, be a problem, and the relevant line of the plugin code above can be changed to the following:

var data = jQuery._data(this[0], 'events')[type];

---

jQuery事件存储在名为events的数据对象中，因此您可以在其中进行搜索:

---

jQuery events are stored in a data object called events, so you could search in this:

var button = $('#myButton');
if (-1 !== $.inArray(onButtonClicked, button.data('events').click)) {
    button.click(onButtonClicked);
}

当然，如果可以构建应用程序，使该代码仅被调用一次，那将是最好的选择.

It would be best, of course, if you could structure your application so this code only gets called once.

可以将其封装到插件中

$.fn.isBound = function(type, fn) {
    var data = this.data('events')[type];

    if (data === undefined || data.length === 0) {
        return false;
    }

    return (-1 !== $.inArray(fn, data));
};

然后您可以致电:

var button = $('#myButton');
if (!button.isBound('click', onButtonClicked)) {
    button.click(onButtonClicked);
}

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