TransactionScope.Complete Metode

Definisi

Ruang nama:

System.Transactions

Rakitan:

System.Transactions.Local.dll

Sumber:

TransactionScope.cs

Menunjukkan bahwa semua operasi dalam cakupan berhasil diselesaikan.

public:
 void Complete();

public void Complete ();

member this.Complete : unit -> unit

Public Sub Complete ()

Pengecualian

InvalidOperationException

Metode ini telah dipanggil sekali.

Contoh

Contoh berikut menunjukkan cara menggunakan TransactionScope kelas untuk menentukan blok kode untuk berpartisipasi dalam transaksi.

// This function takes arguments for 2 connection strings and commands to create a transaction 
// involving two SQL Servers. It returns a value > 0 if the transaction is committed, 0 if the 
// transaction is rolled back. To test this code, you can connect to two different databases 
// on the same server by altering the connection string, or to another 3rd party RDBMS by 
// altering the code in the connection2 code block.
static public int CreateTransactionScope(
    string connectString1, string connectString2,
    string commandText1, string commandText2)
{
    // Initialize the return value to zero and create a StringWriter to display results.
    int returnValue = 0;
    System.IO.StringWriter writer = new System.IO.StringWriter();

    try
    {
        // Create the TransactionScope to execute the commands, guaranteeing
        // that both commands can commit or roll back as a single unit of work.
        using (TransactionScope scope = new TransactionScope())
        {
            using (SqlConnection connection1 = new SqlConnection(connectString1))
            {
                // Opening the connection automatically enlists it in the 
                // TransactionScope as a lightweight transaction.
                connection1.Open();

                // Create the SqlCommand object and execute the first command.
                SqlCommand command1 = new SqlCommand(commandText1, connection1);
                returnValue = command1.ExecuteNonQuery();
                writer.WriteLine("Rows to be affected by command1: {0}", returnValue);

                // If you get here, this means that command1 succeeded. By nesting
                // the using block for connection2 inside that of connection1, you
                // conserve server and network resources as connection2 is opened
                // only when there is a chance that the transaction can commit.   
                using (SqlConnection connection2 = new SqlConnection(connectString2))
                {
                    // The transaction is escalated to a full distributed
                    // transaction when connection2 is opened.
                    connection2.Open();

                    // Execute the second command in the second database.
                    returnValue = 0;
                    SqlCommand command2 = new SqlCommand(commandText2, connection2);
                    returnValue = command2.ExecuteNonQuery();
                    writer.WriteLine("Rows to be affected by command2: {0}", returnValue);
                }
            }

            // The Complete method commits the transaction. If an exception has been thrown,
            // Complete is not  called and the transaction is rolled back.
            scope.Complete();
        }
    }
    catch (TransactionAbortedException ex)
    {
        writer.WriteLine("TransactionAbortedException Message: {0}", ex.Message);
    }

    // Display messages.
    Console.WriteLine(writer.ToString());

    return returnValue;
}

'  This function takes arguments for 2 connection strings and commands to create a transaction 
'  involving two SQL Servers. It returns a value > 0 if the transaction is committed, 0 if the 
'  transaction is rolled back. To test this code, you can connect to two different databases 
'  on the same server by altering the connection string, or to another 3rd party RDBMS  
'  by altering the code in the connection2 code block.
Public Function CreateTransactionScope( _
  ByVal connectString1 As String, ByVal connectString2 As String, _
  ByVal commandText1 As String, ByVal commandText2 As String) As Integer

    ' Initialize the return value to zero and create a StringWriter to display results.
    Dim returnValue As Integer = 0
    Dim writer As System.IO.StringWriter = New System.IO.StringWriter

    Try
    ' Create the TransactionScope to execute the commands, guaranteeing
    '  that both commands can commit or roll back as a single unit of work.
        Using scope As New TransactionScope()
            Using connection1 As New SqlConnection(connectString1)
                ' Opening the connection automatically enlists it in the 
                ' TransactionScope as a lightweight transaction.
                connection1.Open()

                ' Create the SqlCommand object and execute the first command.
                Dim command1 As SqlCommand = New SqlCommand(commandText1, connection1)
                returnValue = command1.ExecuteNonQuery()
                writer.WriteLine("Rows to be affected by command1: {0}", returnValue)

                ' If you get here, this means that command1 succeeded. By nesting
                ' the using block for connection2 inside that of connection1, you
                ' conserve server and network resources as connection2 is opened
                ' only when there is a chance that the transaction can commit.   
                Using connection2 As New SqlConnection(connectString2)
                    ' The transaction is escalated to a full distributed
                    ' transaction when connection2 is opened.
                    connection2.Open()

                    ' Execute the second command in the second database.
                    returnValue = 0
                    Dim command2 As SqlCommand = New SqlCommand(commandText2, connection2)
                    returnValue = command2.ExecuteNonQuery()
                    writer.WriteLine("Rows to be affected by command2: {0}", returnValue)
                End Using
            End Using

        ' The Complete method commits the transaction. If an exception has been thrown,
        ' Complete is called and the transaction is rolled back.
        scope.Complete()
        End Using
    Catch ex As TransactionAbortedException
        writer.WriteLine("TransactionAbortedException Message: {0}", ex.Message)
    End Try

    ' Display messages.
    Console.WriteLine(writer.ToString())

    Return returnValue
End Function

Keterangan

Ketika Anda puas bahwa semua operasi dalam cakupan berhasil diselesaikan, Anda harus memanggil metode ini hanya sekali untuk memberi tahu manajer transaksi bahwa status di semua sumber daya konsisten, dan transaksi dapat dilakukan. Ini adalah praktik yang sangat baik untuk menempatkan panggilan sebagai pernyataan terakhir di using blok.

Untuk informasi selengkapnya tentang bagaimana metode ini digunakan, lihat topik Menerapkan Transaksi Implisit Menggunakan Cakupan Transaksi .

Gagal memanggil metode ini membatalkan transaksi, karena manajer transaksi menginterpretasikan ini sebagai kegagalan sistem, atau pengecualian yang dilemparkan dalam cakupan transaksi. Namun, Anda juga harus mencatat bahwa memanggil metode ini tidak menjamin penerapan transaksi. Ini hanyalah cara untuk memberi tahu manajer transaksi tentang status Anda. Setelah memanggil metode ini, Anda tidak dapat lagi mengakses transaksi sekitar melalui Current properti , dan mencoba melakukannya menghasilkan pengecualian yang dilemparkan.

Pekerjaan penerapan aktual antara manajer sumber daya terjadi pada End Using pernyataan jika TransactionScope objek membuat transaksi. Jika tidak membuat transaksi, komit terjadi setiap kali Commit dipanggil oleh pemilik objek CommittableTransaction. Pada saat itu Manajer Transaksi memanggil manajer sumber daya dan memberi tahu mereka untuk menerapkan atau memutar kembali, berdasarkan apakah metode ini dipanggil pada TransactionScope objek.

Lihat juga

• Menerapkan transaksi implisit menggunakan cakupan transaksi