/// <summary>
/// 开启事务处理。
/// </summary>
/// <param name="il">事务锁定行为（即隔离级别）.</param>
/// <returns></returns>
public DBTransactionController BeginTrans(IsolationLevel?il = null)
{
if (DBA == null || CommandParserAdapter == null)
{
throw (new Exception("无法开启事务，因为尚未初始化 DBA 或 CommandParserAdapter 对象。"));
}
IDbConnection DbConnection = DBA.Connect();
//DbConnection.Open();
IDbTransaction Trans;
if (il == null)
{
Trans = DbConnection.BeginTransaction();
}
else
{
Trans = DbConnection.BeginTransaction(il.Value);
}
IDbCommand DbCommand = DBA.CreateDbCommand();
DbCommand.Connection = DbConnection;
DbCommand.Transaction = Trans;
TransactionDbAccess transDBA = new TransactionDbAccess(DbCommand, this);
DBTransactionController TransController = new DBTransactionController(Trans, transDBA, new ReleaseTransHandler(ReleaseTransaction));
TransactionConnectionCache.RegisterValidTransaction(TransController.UniqueId, DBA, DbConnection);
return(TransController);
}