jQuery-UI可拖动和可排序，beforeStop助手已经运行

Question

当beforeStop singal触发ui.item等于ui.helper时，即该项目已被帮助者替换，我无法访问发起事件的可拖动事件。

这是JavaScript

makeDraggable = function(ID) {
    $('ul#elements > li.element').each(function() {
        $(this).draggable({
            helper: function() {
                return $('<div style="height: 100px; width: 300px; background: #F9FAFA; box-shadow: 5px 5px 1px rgba(0,0,0,0.1); text-align: center; line-height: 100px; font-size: 28px; color: #16A085"><span class="fui-list"></span></div>');
            },
            revert: 'invalid',
            appendTo: 'body',
            connectToSortable: ID,
        });
    });
};

makeSortable = function(el) {
    el.sortable({
        revert: true,
        placeholder: 'drop-hover',
        beforeStop: function(event, ui) {
            console.log(ui.item);
            console.log(ui.helper);
        },
    });
};

makeDraggable('#page1');
makeSortable($('#page1'));

这是可拖动的：

<li class="element element_0 ui-draggable ui-draggable-handle" style="display: list-item;">
    <img src="http://localhost:8000/images/thumbs/header10.png" data-src="http://localhost:8000/elements/header10.html" data-height="567" alt="Site Block">
</li>

我做错了什么？