基础提供程序在打开时失败。连接未关闭。连接的当前状态为连接中。问题

Question

当我尝试使用工作单元存储库从表中提取异步Task函数中的记录时，遇到异常

  

“ System.Data.Entity.Core.EntityException：基础提供程序在打开时失败。---> System.InvalidOperationException：连接未关闭。连接的当前状态为连接中。”

var ProductList= unitOfWork.ProductRepo.Find(x => x.Id== ProductId);

尽管我正在为每个任务创建一个新的unitofwork对象。但对于单线程，它可以正常工作。

  full trace:"TRACE:Task.Execute => Task`1.InnerInvoke => <>c__DisplayClass17_0.<StartMigration>b__0
           EXCEPTION:System.Data.Entity.Core.EntityException: The underlying provider failed on Open. ---> System.InvalidOperationException: The connection was not closed. The connection's current state is connecting.
     at System.Data.ProviderBase.DbConnectionClosedConnecting.TryOpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
     at System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource`1 retry)
     at System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry)
     at System.Data.SqlClient.SqlConnection.Open()
     at System.Data.Entity.Infrastructure.Interception.DbConnectionDispatcher.<Open>b__36(DbConnection t, DbConnectionInterceptionContext c)
     at System.Data.Entity.Infrastructure.Interception.InternalDispatcher`1.Dispatch[TTarget,TInterceptionContext](TTarget target, Action`2 operation, TInterceptionContext interceptionContext, Action`3 executing, Action`3 executed)
     at System.Data.Entity.Infrastructure.Interception.DbConnectionDispatcher.Open(DbConnection connection, DbInterceptionContext interceptionContext)
     at System.Data.Entity.Core.EntityClient.EntityConnection.<Open>b__2()
     at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.<>c__DisplayClass1.<Execute>b__0()
     at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func`1 operation)
     at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute(Action operation)
     at System.Data.Entity.Core.EntityClient.EntityConnection.Open()
     --- End of inner exception stack trace ---
     at System.Data.Entity.Core.EntityClient.EntityConnection.Open()
     at System.Data.Entity.Core.Objects.ObjectContext.EnsureConnection(Boolean shouldMonitorTransactions)
     at System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction[T](Func`1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess)
     at System.Data.Entity.Core.Objects.ObjectQuery`1.<>c__DisplayClass7.<GetResults>b__5()
     at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func`1 operation)
     at System.Data.Entity.Core.Objects.ObjectQuery`1.GetResults(Nullable`1 forMergeOption)
     at System.Data.Entity.Core.Objects.ObjectQuery`1.<System.Collections.Generic.IEnumerable<T>.GetEnumerator>b__0()
     at System.Data.Entity.Internal.LazyEnumerator`1.MoveNext()
     at System.Linq.Enumerable.Count[TSource](IEnumerable`1 source)
     at FS.Migration.Assistant.Assistant.MigrationAssistance.<>c__DisplayClass17_0.<<StartMigration>b__0>d.MoveNext() in "

不是我可以粘贴的所有代码，这是每次任务运行时都使用DBconrtext建立新连接的代码段

  Task.Run(async () =>
            {

                Model.MigrationModel.ReadyToMigrate ready = new ReadyToMigrate();
                unitOfWork = new UnitOfWork(new ContextMigrationEntities());
                try
                {
}Catch(Exception ex)
{
}
});