DependentTransaction Classe

Definizione

public ref class DependentTransaction sealed : System::Transactions::Transaction

public sealed class DependentTransaction : System.Transactions.Transaction

[System.Serializable]
public sealed class DependentTransaction : System.Transactions.Transaction

type DependentTransaction = class
    inherit Transaction

[<System.Serializable>]
type DependentTransaction = class
    inherit Transaction

Public NotInheritable Class DependentTransaction
Inherits Transaction

Ereditarietà

Object

Transaction

DependentTransaction

Attributi

SerializableAttribute

Esempio

Nell'esempio seguente viene illustrato come creare una transazione dipendente.

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

Commenti

DependentTransaction è un clone di un Transaction oggetto creato usando il DependentClone metodo . L'unico scopo è consentire all'applicazione di rimanere inattivi e garantire che la transazione non possa eseguire il commit mentre il lavoro è ancora in esecuzione sulla transazione (ad esempio, in un thread di lavoro).

Quando il lavoro svolto all'interno della transazione clonata viene finalmente completato e pronto per il commit, può informare l'autore della transazione usando il Complete metodo . È quindi possibile mantenere la coerenza e la correttezza dei dati.

L'enumerazione DependentCloneOption viene utilizzata per determinare il comportamento al commit. Questo controllo del comportamento consente a un'applicazione di venire a riposo, oltre a fornire supporto per la concorrenza. Per altre informazioni sull'uso di questa enumerazione, vedere Managing Concurrency with DependentTransaction .For more information on how this enumeration is used, see Managing Concurrency with DependentTransaction.

Proprietà

Metodi

Eventi

Implementazioni dell'interfaccia esplicita

Si applica a

Thread safety

Questo tipo è thread-safe.

Vedi anche

• Gestione della concorrenza con DependentTransaction