即使未更改，也会选择 JQuery 检测下拉值 [英] JQuery detect dropdown value is selected even if it's not changed

问题描述

使用 JQuery 或 JavaScript，我想检测用户何时选择了一个值，即使他们没有更改已选择的值.

Using JQuery or JavaScript, I want to detect when a user selects a value, even if they don't change the already selected value.

如何实现?

我试过了 -

$('#MyID').select(function(){ /*my function*/ });

和

$('#MyID').change(function(){ /*my function*/ }); //nothing changing, so this fails

但它们不起作用.

示例 - 我有一个包含年份列表的下拉列表，没有选择任何内容，用户选择1976"，我运行一个函数.选择1976"后，用户再次单击下拉菜单并选择1976"再次，我想再次运行该功能.

Example - I have a dropdown with a list of years in it with nothing selected, the user selects "1976", I run a function. With "1976" selected, the user clicks on the dropdown again and selects "1976" again, I want to run the function again.

推荐答案

所有系统运行(至少在第二次点击时...)

all systems go (on second click at least...)

将开关设置为在选择时运行，并在捕获和/或在 blur 上重置开关.

Set a switch to run on selection, and reset the switch after it's captured and/or on blur.

var go = false;//switch off
$('#MyID').on('click',function() {//on click
    if (go) {//if go
        //do stuff here with $(this).val()
        go = false;//switch off
    } else { go = true; }//if !go, switch on
}).on('blur', function() { go = false; });//switch off on blur

做了一个小提琴:http://jsfiddle.net/filever10/2XBVf/

对于键盘支持也是如此，这样的事情应该可以工作.

edit: for keyboard support as well, something like this should work.

var go = false;//switch off
$('#MyID').on('focus active click',function() {//on focus/active
    doit($(this));//do it
}).on('change', function() {
    go=true;//go
    doit($(this));//and doit
}).on('blur', function() { go = false; });//switch off on blur

function doit(el) {
    if (go) {//if go
        //do stuff here with el.val()
        go = false;//switch off
    } else {go=true}//else go
}

做了一个小提琴:http://jsfiddle.net/filever10/TyGPU/

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