1、直接在客户端统计，动态的修改Grid

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2、代码如下

buttons: [{
	text: '查询',
	handler: function() {
		var a = Ext.getCmp('wholesale-query-form').form.getValues();
		var s = Ext.StoreMgr.lookup('wholesaleReportStore');
		s.load({
			params:a,
			callback:function(r,options,success){  
				if(!success){
					alert("数据加载失败！");
				}
				else{
					//合计行
					var sumc = 0; //数量合计
					var sumw = 0; //重量合计
					var suma = 0; //总金额合计
					var avgp = 0; //平均价合计
					
					var wgrid = Ext.getCmp("wholesale-report-grid")
					wgrid.store.each(function(record){  
						sumc += Number(record.data.scount);
						sumw += Number(record.data.sweight);
						suma += Number(record.data.samount);
				    });
					avgp = (suma/sumw).toFixed(2);
					
					var n = wgrid.getStore().getCount();// 获得总行数   
					var p = new Ext.data.Record({
						salerName: '总计:',  
						scount:sumc,
						sweight:sumw,
						samount:suma,
						aprice:avgp
				    });  
					wgrid.store.insert(n, p);// 插入到最后一行 
				}
			}
		});
	}
	}]

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