javascript - jQuery，也会在已选择的选项上触发更改

Question

<分区>

Answer 1

编辑: IE 不能很好地处理它! :(

要支持 IE，您可以使用:

--DEMO--

$(document).ready(function () {
    var con = $('#console');
    $('select').change(function () {        
        /* change also on already selected option */
        con.append('- ' + $(this).val() + '<br/>');
        //$(this).blur();
    }).change().bind('mousedown', function () {
        this.selectedIndex = -1;
        this.selectedIndex = $(this).find('option:selected').index();
    });
});

看看这是否符合您的需求:

--DEMO--

$(document).ready(function () {
    var con = $('#console');
    $('select').change(function () {        
        /* change also on already selected option */
        con.append('- ' + $(this).val() + '<br/>');
    }).change().bind('mousedown', function () {
        //on mousedown, clone SELECT element to display current selected value
        // this would be empty value otherwise when setting current selected index
        // NOTE: seems to be still not as good on IE...
        // FF would need to redefine some margin/padding
        if (!$(this).data('cloned')) $(this).data('cloned', $(this).clone().css({
            position: 'absolute',
            pointerEvents: 'none',
            top: this.offsetTop,
            left: this.offsetLeft,
            margin: 0
        }).appendTo('body'));
        // here set selectedIndex of SELECT element to not defined index
        // this would let on change event to be fired in all cases
        this.selectedIndex = -1;
    }).blur(function(){
        // on blur, remove cloned SELECT element and reset specific data object
        if ($(this).data('cloned')) {
            this.value = $(this).data('cloned').val();
            $(this).data('cloned').remove();
            $(this).data('cloned', null);
        }
    });
});