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DependentTransaction Class

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)

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

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()
			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
		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

System.Object
  System.Transactions.Transaction
    System.Transactions.DependentTransaction

This type is thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

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

.NET Framework

Supported in: 3.5, 3.0, 2.0
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