C#

private void EnumerateTables(ComboBox cmb, String databaseName, bool isAccess)
        {
            //cmb.Items.Clear();
            if (!isAccess)
            {
                var srv = new Server(Properties.Settings.Default.ServerInstance);
                srv.Databases.Refresh();
                foreach (Database db in srv.Databases)
                {
                    if (db.Name == cmbboxSqlDb.Text)
                        
                    {
                        BindingSource bs = new BindingSource();
                        bs.DataSource = db.Tables;
                        bs.DataMember = "Name";
                        cmb.DataSource = bs;
                        //var tableEnumerator = db.Tables.GetEnumerator();

                        //while (tableEnumerator.MoveNext())
                        //{
                        //    cmb.Items.Add(((Table)tableEnumerator.Current).Name);
                        //}
                    }
                }
            }
            else
            {
                
                if (AccessConnString != null)
                {
                    var conn = new OleDbConnection(AccessConnString);

                    // open the connection to the database 
                    conn.Open();
                    // this.Dispose();

                    // Get the Tables
                    var schemaTable = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new Object[] { null, null, null, "TABLE" });

                    // Store the table names in the class scoped array list of table names
                    for (int i = 0; i < schemaTable.Rows.Count; i++)
                    {
                      cmb.Items.Add(schemaTable.Rows[i].ItemArray[2].ToString());
                    }

                }
            }
        }

Thread t = new Thread(delegate()
            {
                SqlConnection con = null;

                try
                {
                    string conStr = "CONNECTIONSTRING GOES HERE"; 
                    con = new SqlConnection(conStr);
                    con.Open();
                    datenbankStatus(true); // raise event - show connect icon
                }
                catch (Exception ex)
                {
                    datenbankStatus(false);  // raise event - show disconnect icon
                }
                finally
                {
                    if (con != null && con.State == System.Data.ConnectionState.Open) con.Close();
                }
            });
            t.IsBackground = true;
            t.Start();