Transaction.DependentClone(DependentCloneOption) Метод

public:
 System::Transactions::DependentTransaction ^ DependentClone(System::Transactions::DependentCloneOption cloneOption);

public System.Transactions.DependentTransaction DependentClone(System.Transactions.DependentCloneOption cloneOption);

member this.DependentClone : System.Transactions.DependentCloneOption -> System.Transactions.DependentTransaction

Public Function DependentClone (cloneOption As DependentCloneOption) As DependentTransaction

Параметры

Возвращаемое значение

Объект, DependentTransaction представляющий зависимый клон.

Примеры

В следующем примере показано, как создать зависимые транзакции.

static void Main(string[] args)
{
    try
    {
        using (TransactionScope scope = new TransactionScope())
        {
            // Perform transactional work here.

            //Queue work item
            ThreadPool.QueueUserWorkItem(new WaitCallback(WorkerThread), Transaction.Current.DependentClone(DependentCloneOption.BlockCommitUntilComplete));

            //Display transaction information
            Console.WriteLine("Transaction information:");
            Console.WriteLine("ID:             {0}", Transaction.Current.TransactionInformation.LocalIdentifier);
            Console.WriteLine("status:         {0}", Transaction.Current.TransactionInformation.Status);
            Console.WriteLine("isolationlevel: {0}", Transaction.Current.IsolationLevel);

            //Call Complete on the TransactionScope based on console input
            ConsoleKeyInfo c;
            while (true)
            {
                            Console.Write("Complete the transaction scope? [Y|N] ");
                c = Console.ReadKey();
                Console.WriteLine();

                if ((c.KeyChar == 'Y') || (c.KeyChar == 'y'))
                {
                    //Call complete on the scope
                    scope.Complete();
                    break;
                }
                else if ((c.KeyChar == 'N') || (c.KeyChar == 'n'))
                {
                    break;
                }
            }
        }
    }
    catch (System.Transactions.TransactionException ex)
    {
        Console.WriteLine(ex);
    }
    catch
    {
        Console.WriteLine("Cannot complete transaction");
        throw;
    }
}

private static void WorkerThread(object transaction)
{
    //Create a DependentTransaction from the object passed to the WorkerThread
    DependentTransaction dTx = (DependentTransaction)transaction;

    //Sleep for 1 second to force the worker thread to delay
    Thread.Sleep(1000);

    //Pass the DependentTransaction to the scope, so that work done in the scope becomes part of the transaction passed to the worker thread
    using (TransactionScope ts = new TransactionScope(dTx))
    {
        //Perform transactional work here.

        //Call complete on the transaction scope
        ts.Complete();
    }

    //Call complete on the dependent transaction
    dTx.Complete();
}

Public Shared Sub Main()
    Try
        Using scope As TransactionScope = New TransactionScope()

            'Perform transactional work here.

            'Queue work item
            ThreadPool.QueueUserWorkItem(AddressOf WorkerThread, Transaction.Current.DependentClone(DependentCloneOption.BlockCommitUntilComplete))

            'Display transaction information
            Console.WriteLine("Transaction information:")
            Console.WriteLine("ID:             {0}", Transaction.Current.TransactionInformation.LocalIdentifier)
            Console.WriteLine("status:         {0}", Transaction.Current.TransactionInformation.Status)
            Console.WriteLine("isolationlevel: {0}", Transaction.Current.IsolationLevel)

            'Call Complete on the TransactionScope based on console input
            Dim c As ConsoleKeyInfo
            While (True)

                Console.Write("Complete the transaction scope? [Y|N] ")
                c = Console.ReadKey()
                Console.WriteLine()
                If (c.KeyChar = "Y") Or (c.KeyChar = "y") Then
                    scope.Complete()
                    Exit While
                ElseIf ((c.KeyChar = "N") Or (c.KeyChar = "n")) Then
                    Exit While
                End If
            End While
        End Using

    Catch ex As TransactionException
        Console.WriteLine(ex)
    Catch
        Console.WriteLine("Cannot complete transaction")
        Throw
    End Try
End Sub

Public Shared Sub WorkerThread(ByVal myTransaction As Object)

    'Create a DependentTransaction from the object passed to the WorkerThread
    Dim dTx As DependentTransaction
    dTx = CType(myTransaction, DependentTransaction)

    'Sleep for 1 second to force the worker thread to delay
    Thread.Sleep(1000)

    'Pass the DependentTransaction to the scope, so that work done in the scope becomes part of the transaction passed to the worker thread
    Using ts As TransactionScope = New TransactionScope(dTx)
        'Perform transactional work here.

        'Call complete on the transaction scope
        ts.Complete()
    End Using

    'Call complete on the dependent transaction
    dTx.Complete()
End Sub

Комментарии

Зависимый транзакция — это транзакция, результат которой зависит от результата транзакции, из которой она была клонирована.

Параметр cloneoption определяет тип создаваемой зависимой транзакции. Если с помощью зависимой транзакции создается BlockCommitUntilComplete, она блокирует процесс фиксации транзакции до истечения времени ожидания транзакции или Complete вызывается в ней DependentTransaction. Если он создается с RollbackIfNotCompleteпомощью, он автоматически прерывает транзакцию, если Commit вызывается перед Complete вызовом.DependentTransaction

См. также раздел

• Управление параллелизмом с помощью DependentTransaction