DependentTransaction Class

Note: This class is new in the .NET Framework version 2.0.

Describes a clone of a transaction providing guarantee that the transaction cannot be committed until the application comes to rest regarding work on the transaction. This class cannot be inherited.

Namespace: System.Transactions
Assembly: System.Transactions (in system.transactions.dll)

<SerializableAttribute> _
Public NotInheritable Class DependentTransaction
	Inherits Transaction
Dim instance As DependentTransaction

/** @attribute SerializableAttribute() */ 
public final class DependentTransaction extends Transaction
public final class DependentTransaction extends Transaction

The DependentTransaction is a clone of a Transaction object created using the DependentClone method. Its sole purpose is to allow the application to come to rest and guarantee that the transaction cannot commit while work is still being performed on the transaction (for example, on a worker thread).

When the work done within the cloned transaction is finally complete and ready to be committed, it can inform the creator of the transaction using the Complete method. Thus you can preserve the consistency and correctness of data.

The DependentCloneOption enumeration is used to determine the behavior on commit. This behavior control allows an application to come to rest, as well as provides concurrency support. For more information on how this enumeration is used, see Managing Concurrency with DependentTransaction.

The following example shows you how to create a dependent transaction.

Public Shared Sub Main()
        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()
                If (c.KeyChar = "Y") Or (c.KeyChar = "y") Then
                    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("Cannot complete transaction")
    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

    '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
    End Using

    'Call complete on the dependent transaction
End Sub


This type is safe for multithreaded operations.

Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0

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