DataReader associated with this Command which must be closed first

问题

I am getting the following error;

"There is already an open DataReader associated with this Command which must be closed first."

is it because I have used the reader in foreach loop ? or what the problem might be ? Regards BK

foreach( Apple a in listApple )
{


....
                   using (SmartSqlReader reader = Db.CurrentDb.ExecuteReader(sp))
                    {
                        while (reader.Read())
                        {
                            a.blablabla += reader.GetInt32("BLA_BLA_BLA"); 
                        }
                    }


.....

}

回答1:

Try the following:

using (SmartSqlReader reader = Db.CurrentDb.ExecuteReader(sp))
 {
  while (reader.Read())
  {
   a.blablabla += reader.GetInt32("BLA_BLA_BLA"); 
  }
  reader.Close();
 }

回答2:

Have you implemeneted the SmartSqlReader to close when it's disposed? The regular data readers implement the IDisposable interface and calls Close from the Dispose method.

If you don't close it properly it will keep the Command object occupied until the garbage collector will find the reader and clean it up.

回答3:

Add reader.Close() to close the SmartSqlReader

来源：https://stackoverflow.com/questions/1605504/datareader-associated-with-this-command-which-must-be-closed-first