EasyUI datagrid表数据某列总和

效果如图：

代码如下：

<table id="dg"></table>
<script>
    $(function () {
        $('#dg').datagrid({
            singleSelect: true,
            onLoadSuccess: compute,//加载完毕后执行计算
            url: 'product.json', fitColumns: true, pagination: true, pageSize: 3,
            title: '统计easyui datagrid某列之和显示在对应列下面',
             400,
            height: 300,
            columns: [[{ field: 'itemid',  80, title: 'Item ID' },
            { field: 'productname',  100, editor: 'text', title: 'Product Name' },
            { field: 'listprice',  80, align: 'right', title: 'List Pirce' },
            { field: 'unitcost',  80, align: 'right', title: 'Unit Cost' }]]
        });
    });
    function compute() {//计算函数
        var rows = $('#dg').datagrid('getRows')//获取当前的数据行
        var ptotal = 0//计算listprice的总和
            , utotal = 0;//统计unitcost的总和
        for (var i = 0; i < rows.length; i++) {
            ptotal += parseFloat(rows[i]['listprice']);
            utotal += parseFloat(rows[i]['unitcost']);
　　　　}

//新增一行显示统计信息
        $('#dg').datagrid('appendRow', { itemid: '<b>统计：</b>', listprice: ptotal.toFixed(1), unitcost: utotal });
    }
    </script>

附：

{"total":28,"rows":[
{"productname":"Koi","unitcost":10.00,"listprice":36.50,"itemid":"EST-1"},
{"productname":"Dalmation","unitcost":12.00,"listprice":18.50,"itemid":"EST-10"},
{"productname":"Rattlesnake","unitcost":12.00,"listprice":38.50,"itemid":"EST-11"},
{"productname":"Rattlesnake","unitcost":12.00,"listprice":26.50,"itemid":"EST-12"},
{"productname":"Iguana","unitcost":12.00,"listprice":35.50,"itemid":"EST-13"}
]}