[EF]事务处理

EF支持事务处理操作，以下语句会获取当前DbContext对象专用的DbContextTransaction()事务处理对象

DbContextTransaction transaction=context.Database.BeginTransaction();
获取transaction之后，期间任何与context有关的数据操作均会纳入此事务处理的范围中，调用transaction.Commit方法即可完成事务处理，若要放弃事务处理，则调用transaction.Rollback方法即可达到目的。
//using TransactionsDemo.Model;

        using (KTStoreContext context = new KTStoreContext())
            {
                using (var transaction = context.Database.BeginTransaction())
                {
                    try
                    {
                        var products = context.Products;
                        foreach (Product product in products)
                        {
                            int p = (int)(product.Price * 0.5);
                            product.SPrice = p;
                        }
                        int c = context.SaveChanges();
                        transaction.Commit();
                        Console.WriteLine("更新了 {0} 项数据", c);
                    }
                    catch (Exception ex)
                    {
                        transaction.Rollback();
                        Console.WriteLine("事务处理失败");
                    }
                }
            }
            Console.ReadKey();