这个BUG让我找了3天

public datetime UserLastOnline(string UID, string CustomerID)
{
  datetime ret;
  IDbConnection con = null;
  try
  {
  con = new SqlConnection();
  con.ConnectionString = InstantIssue_Utility.DecryptConnectionString(connectionString);
  con.Open();
  IDbCommand cmd = con.CreateCommand();
  cmd.Connection = con;
  string sql_command = "select LastActivityTimeStamp from UserToken where UserId1 = '" + UID + "' and Status = 'A'";
  IDbCommand com = con.CreateCommand();
  com.CommandType = CommandType.Text;
  com.CommandText = sql_command;
  IDataReader reader = com.ExecuteReader();
  while (reader.Read())
  {
   
    ret = Convert.ToDateTime(reader[0]);
  }
  reader.Close();
  com.Cancel(); 
  reader.Close();
  com.Cancel();
  return ret;
  }
  catch (InstantIssue_Exception)
  { }
 
 
  con.Close();
     
}

竟然漏连接了>_<
我太年轻了