easyui datagrid 多行删除问题

@using XStudio.XWebFramework.Extensions
<script type="text/javascript" defer="defer">
    var List = {};
   
    List.DeleteSelected = function (e) {
        var selected = $("#tbList").datagrid("getSelections");
        if (selected.length == 0) {
            alert("请选择要删除的文章？");
            return;
        }
        var idString = "";
        $.each(selected, function (index, item) {
            idString += item.ArticleID + ",";
        });
       
        if (!confirm("确认要删除选中文章信息？"))
            return;
        $.post($(e).attr("href"), { id: idString }, function (data) {
            if (data.IsOK) {
                $("#tbList").datagrid("clearSelections");//解决方法：在删除数据成功后清空所有的已选择项
                $('#tbList').datagrid('reload');
            }
            else
                alert(data.Description);
        });
    }
    $(document).ready(function () {
        $('#tbList').datagrid({ pagination: true });
    });
</script><div class="tt-attach">
    <ul class="op">
        @Html.WebPartButton("删除选中", "Delete", null, new { onclick = "List.DeleteSelected(this); return false;", @class = "btn-remove" })
    </ul>
</div>
<div style="padding: 5px 20px 5px 10px;">
    <table id="tbList" striped="true"  rownumbers="true" fix="true"  fitColumns="true" title=""
      idfield="ArticleID" checkbox="true" url="@Url.Action("ListData")">
        <thead>
            <tr>
                <th field="ArticleID" checkbox="true" width="30">
                </th>
            </tr>
        </thead>
    </table>
</div>