Getting the position of the element in a list when

问题:

I have a sortable list like this one: http://jqueryui.com/demos/sortable

Is it possible to get the start and end position of the element in the list, when it has been moved? I'm talking about their position number, in the list.

For example, if I move element 2 to position 5 in the list, I'd like to assign those two numbers to variables.

I'm new to jQuery - any help would be much appreciated.

回答1:

• demo: http://so.lucafilosofi.com/getting-the-position-of-the-element-in-a-list-when-its-drag-dropped-ui-sortable/

SOLUTION:

$(function() {
    $('ul#sortable').sortable({
        start: function(event, ui) {
            var start_pos = ui.item.index();
            ui.item.data('start_pos', start_pos);
        },
        update: function(event, ui) {
            var start_pos = ui.item.data('start_pos');
            var end_pos = ui.item.index();
            alert(start_pos + ' - ' + end_pos);
        }
    });
});

• NOTE: Updated to make use of jQuery data() method under advice of Alconja

回答2:

I believe what you are looking to do is done with the serialize method. Serialize is get the new order of the list.

回答3:

For some reason ui.item.index() did not work for me.

This did:

update: function (event, ui) 
{
    var index = $('li', $(ui.item).parent()).index(ui.item);
    alert(index);
}