SqlConnection连接超时的时间控制

        var alive = true;
        string error = null;
        var success = false;

        // ReSharper disable AccessToModifiedClosure
        // ReSharper disable UseObjectOrCollectionInitializer
        var thread = new Thread(() =>
                                    {
                                        try
                                        {
                                            var connection = new SqlConnection(connectionString);
                                            connection.Open();
                                            connection.Close();

                                            if (alive)
                                                success = true;
                                        }
                                        catch (SqlException ex)
                                        {
                                            if (alive)
                                                error = ex.Message;
                                        }
                                        catch (ThreadAbortException)
                                        {
                                        }
                                        finally
                                        {
                                            if (connection.State == ConnectionState.Open)
                                                connection.Close();
                                        }
                                    });
        // ReSharper restore AccessToModifiedClosure
        // ReSharper restore UseObjectOrCollectionInitializer
        thread.IsBackground = true;
        var sw = Stopwatch.StartNew();
        thread.Start();

        var timeout = TimeSpan.FromSeconds(3);
        while (sw.Elapsed < timeout)
            thread.Join(TimeSpan.FromMilliseconds(200));
        sw.Stop();

        if (!success)
        {
            alive = false;
            throw new Exception(error ?? "Connection timeout, please check the connection string.");
        }