.NET中 关于脏读 不可重复读与幻读的代码示例(2)

比喻：A在做源代码审查，在审查的过程中获取了两次源代码，在这两次获取期间B修改了源代码，B修改的很可能是A审查过的代码，而这部分代码可能不符合规范了。

代码示例

复制代码 代码如下:

[TestMethod]
         public void 不可重复读_测试()
         {
             var autoResetEvent = new AutoResetEvent(false);

             var transactionOptions1 = new TransactionOptions { IsolationLevel = IsolationLevel.ReadCommitted };
             var transactionOptions2 = new TransactionOptions { IsolationLevel = IsolationLevel.ReadCommitted };

             using (var ts1 = new TransactionScope(TransactionScopeOption.Required, transactionOptions1))
             {
                 //前置条件
                 using (var context = new TestEntities())
                 {
                     Assert.AreEqual("李妞妞", context.Tables.First().Name);
                 }

                 ThreadPool.QueueUserWorkItem(data =>
                 {
                     using (var ts2 = new TransactionScope(TransactionScopeOption.Required, transactionOptions2))
                     {
                         //修改数据
                         using (var context = new TestEntities())
                         {
                             context.Tables.First().Name = "段光伟";
                             context.SaveChanges();
                         }

                         ts2.Complete();   
                     }

                     autoResetEvent.Set();
                 });

                 autoResetEvent.WaitOne();

                 //不可重复读测试
                 using (var context = new TestEntities())
                 {
                     Assert.AreEqual("段光伟", context.Tables.First().Name);
                 }
             }
         }

定义：A事务读取了两次数据，在这两次的读取过程中B事务添加了数据，A事务的这两次读取出来的集合不一样了（幻读）。