EasyUI DataGird动态生成列

<table id="dg"></table>

<script>...
 function easyUIDataGrid(medid) ...{
            var $datagrid = ...{};
            var columns = new Array();

            $datagrid.title = "";
            $datagrid.height = $(window).height() - 31;
            $datagrid.width = $(window).width();
            $datagrid.sortName = "dt";
            $datagrid.sortOrder = "desc";
            $datagrid.idField = "id";

            var param = ...{ "medid": medid };
            $.ajax(...{
                url: 'getCol.page',
                type: 'post',
                data: "medid=" + medid,
                dataType: "json",
                async: false,
                success: function (returnValue) ...{
　　　　　　　　　　　　//异步获取要动态生成的列 别名，宽度也可以
                    var arr = returnValue;
                    $.each(arr, function (i, item) ...{
                        columns.push(...{ "field": item.colname, "title": item.colalias, "width": 100, "sortable": true });
                    });
                    $datagrid.columns = new Array(columns);
                    $('#dg').datagrid($datagrid);
                    
                }
            });

        }
</script>