easyui datagrid 后台返回所有數據，前台分頁

function pagerFilter(data) {
   
    if (typeof data.length == 'number' && typeof data.splice == 'function') { //判斷數據是否是數組
        data = {
            total: data.length,
            rows: data
        }
    }
    let dg = $(this);
    let opts = dg.datagrid('options');
    let pager = dg.datagrid('getPager');
    pager.pagination({
        beforePageText: “頁”,
        afterPageText: “頁，共{pages}頁”,
        displayMsg: “顯示{from}到{to}，共{total}條記錄”,
        onSelectPage: function (pageNum, pageSize) {
            opts.pageNumber = pageNum;
            opts.pageSize = pageSize;
            pager.pagination('refresh', {
                pageNumber: pageNum,
                pageSize: pageSize
            });
            dg.datagrid('loadData', data);
        }
    });
    if (!data.originalRows) {
        data.originalRows = (data.rows);
    }
    let start = (opts.pageNumber - 1) * parseInt(opts.pageSize);
    let end = start + parseInt(opts.pageSize);
    data.rows = (data.originalRows.slice(start, end));
    return data;
}

$(function () {//加載數據
 $('#id名').datagrid({loadFilter: pagerFilter}).datagrid('loadData', data);
 });