Ext将record中的参数转化为json格式传递

　　　　　　　var grid = this.down("conditiongrid");
            var store = grid.getStore();
            var array = new Array();
            for(var i=0;i<store.getCount();i++){
                var record = store.getAt(i);
                if (record.get(‘useCondition‘) == true) {
                    array.push({
                        paraName : record.get(‘paramName‘),
                        value : record.get(‘conditionValue‘)
                    });
                }
            }
            var obj=Ext.JSON.encode(array);
            this.fireEvent(‘paramsSelected‘,obj);