与linq的饼图

Question

我使用linq查询绑定Microsoft饼图，但没有图表显示屏幕仍为空白 这是我的代码

 adoentityEntities objSlTestEntities = new adoentityEntities();
                var query = from c in objSlTestEntities.tblcategories
                            join p in objSlTestEntities.tblproducts on c.CTID equals p.CTID
                            group c by new { c.CTID, p.Name } into er
                            select new { Title = er.Select(item => item.Title), no = er.Count(), er.Key.Name };

                SalesChart.DataSource = query;
                SalesChart.DataBind();