c#4 0-我這段代碼有什麼問題？

我這段代碼有什麼問題？

var queryResults = from c in customers group c by c.Region into cg select new {totalSales=cg.Sum(c=>c.Sales),Region=cg.Key};

        var orderedResults = from cg in queryResults orderby cg.totalSales descending select cg;

                    問題出在C=>c.Sales
                     new Customer{ID="T",City="Lima",Country="Peru",Region="South America",Sales="2002"}     

最佳回答：

cg.Sum(c=>Convert.ToInt32(c.Sales))看看