如果顯示匯總記錄則需設置頁腳屬性：
首先設置showFooter:true,
然后后台計算出合計數據，一起傳過來，類似如下：
{"total":28,"rows":[
{"productid":"FI-SW-01","unitcost":10.00,"status":"P","listprice":36.50,"attr1":"Large","itemid":"EST-1"},
{"productid":"K9-DL-01","unitcost":12.00,"status":"P","listprice":18.50,"attr1":"Spotted Adult Female","itemid":"EST-10"},
{"productid":"RP-SN-01","unitcost":12.00,"status":"P","listprice":28.50,"attr1":"Venomless","itemid":"EST-11"},
{"productid":"RP-SN-01","unitcost":12.00,"status":"P","listprice":26.50,"attr1":"Rattleless","itemid":"EST-12"},
{"productid":"RP-LI-02","unitcost":12.00,"status":"P","listprice":35.50,"attr1":"Green Adult","itemid":"EST-13"},
{"productid":"FL-DSH-01","unitcost":12.00,"status":"P","listprice":158.50,"attr1":"Tailless","itemid":"EST-14"},
{"productid":"FL-DSH-01","unitcost":12.00,"status":"P","listprice":83.50,"attr1":"With tail","itemid":"EST-15"},
{"productid":"FL-DLH-02","unitcost":12.00,"status":"P","listprice":63.50,"attr1":"Adult Female","itemid":"EST-16"},
{"productid":"FL-DLH-02","unitcost":12.00,"status":"P","listprice":89.50,"attr1":"Adult Male","itemid":"EST-17"},
{"productid":"AV-CB-01","unitcost":92.00,"status":"P","listprice":63.50,"attr1":"Adult Male","itemid":"EST-18"}
],"footer":[
{"unitcost":19.80,"listprice":60.40,"productid":"Average:"},
{"unitcost":198.00,"listprice":604.00,"productid":"Total:"}
]}
注意：“footer”中的數據是一個與主表數據格式一樣的表格，字段與之對應，我的處理方式是新建一個Datatable，然后傳到頁面中。
DataTable footer = new DataTable();
footer.Columns.Add("unitcost", typeof(string));
DataRow drfooter = footer.NewRow();
drfooter["unitcost"] = "合計：" + sum;
footer.Rows.Add(drfooter);
需要匯總某一列，在新表中只加那一列即可。