ExtJS 折线图趟过的坑

   storeBar.load({
                params: { SDate: bTime, EDate: eTime, ResourceId: resourceid },
                callback: function (records, operation, success) {                   
                    var axesItem = leftLine.axes.items;
                    axesItem[0].maximum = records[0].data.MaxNum;
                    axesItem[0].majorTickSteps = 4;
                    leftLine.surface.removeAll();
                    leftLine.redraw(false);
                }
            });