如何取消绑定事件

Question

I'm binding a dropdown

("#dropdownlist").change(function(){
    //Do stuff
});

The above code gets called many times.

How can I unbind this event before binding it each time?

Answer 1

您可以使用unbind()方法：

$('#dropdownlist').unbind('change');

Answer 2

您可以使用一个而不是绑定：

("#dropdownlist").one('change',function(){});

Answer 3

Use following logic:

var f = function () {

}

$('#xx').bind('change', f); // for bind function f
$('#xx').unbind('change', f); // for unbind unbind function f

Answer 4

Additionally jQuery supports namespaces.

For example say you have change handlers that do validation and change handlers that do help text hovering.

You could register:

$("#foo").bind("change.validation", doValidation() );

and

$("#foo").bind("change.helptext", toggleHelptext() );

and then you can unbind a specific set before re-adding validation, eg

$("#foo").unbind("change.validation");
$("#foo").bind("change.validation", doValidation() );

HTH Alex