extjs 页面打开时表格自动加载后台传来的json数据

           var d = new Date();
            var ymd = new Date(d.getFullYear(),(d.getMonth()),d.getDate());
            var dd = ymd.format('Y-m-d'); // 当前时间  
          
            d.setDate(d.getDate()-3);
            var ymd2 = new Date(d.getFullYear(),(d.getMonth()),d.getDate());
            var dd2 = ymd2.format('Y-m-d');// 3天前日期
            
            var hp=    new Ext.data.HttpProxy({
            url : 'initErrorInfo.action?queryStartDate='+dd2+'&queryEndDate='+dd
            });
            
            var errorInfoLook = Ext.data.Record.create([
                {name : 'areaCode'},
                {name : 'errMsg'},
                {name : 'errDis'}
            ]);
            
            
            //最近3天的待人工工单处理效率
            var errorInfoStore = new Ext.data.Store({// 配置分组数据集
                proxy : hp,
                reader : new Ext.data.JsonReader({
                            id : "errorInfo",
                            totalProperty : 'results',
                            root : 'items'
                        }, errorInfoLook),
                remoteSort : true
            });
    
        errorInfoStore.load();    

var grid = new Ext.grid.GridPanel({
                title : '错误信息查询结果',
                //applyTo : 'grid-div',
                 width : Ext.getBody().getViewSize().width/2,
                loadMask:true,
                height : Ext.getBody().getViewSize().height -160,
                frame : true,
               renderTo:'grid-div3',
                store : errorInfoStore,
                columns : [
                    new Ext.grid.RowNumberer({20}),
                    {header:"地市",100,dataIndex:'areaCode',sortable:true},
                    {header:"错误原因",200,dataIndex:'errMsg',sortable:true},
                    {header:"错误描述",270,dataIndex:'errDis',sortable:true}
                    ],
                // bbar:[exportButton]
                 bbar:pageAA
            });

若点击查询按钮 刷新表格数据：

function  statisByDev()
    {
        //submitForm();
        var date1 = document.getElementById('date1errorInfo').value;
        var date2 = document.getElementById('date2errorInfo').value;
        var d = new Date(); 
        var year = d.getYear(); 
        var month = d.getMonth()+1; 
        var date = d.getDate(); 
        var day = d.getDay(); 
        var curDateTime= year;
        if(month>9)
         curDateTime = curDateTime +"-"+month;
        else
         curDateTime = curDateTime +"-0"+month;
        if(date>9)
         curDateTime = curDateTime +"-"+date;
        else
         curDateTime = curDateTime +"-0"+date;
        if(date1 != "" && date2 != ""){
            if(date1 >= date2){
                Ext.MessageBox.alert("错误","结束日期应大于起始日期");
                return false;
            }
        }
        
        //起始日期
        var queryStartDateValue=document.getElementById('date1errorInfo').value;
        //结束日期
        var queryEndDateValue=document.getElementById('date2errorInfo').value;
         hp.conn.url='ewsErrorInfo.action?queryStartDate='+queryStartDateValue+'&queryEndDate='+queryEndDateValue;
        errorInfoStore.reload({params:{start:0, limit:pageSize}});    

    }

总之通过hp.conn.url可以控制。