TransactionScope.Complete 方法

定義

表示範圍內的所有作業都已成功完成。Indicates that all operations within the scope are completed successfully.

public:
 void Complete();
public void Complete ();
member this.Complete : unit -> unit
Public Sub Complete ()

例外狀況

已經呼叫這個方法一次。This method has already been called once.

範例

下列範例示範如何使用TransactionScope類別來定義要參與交易的程式碼區塊。The following example demonstrates how to use the TransactionScope class to define a block of code to participate in a transaction.

// 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

備註

當您滿意範圍內的所有作業都順利完成時,您應該只呼叫這個方法一次,通知交易管理員所有資源的狀態都是一致的,而且可以認可交易。When you are satisfied that all operations within the scope are completed successfully, you should call this method only once to inform that transaction manager that the state across all resources is consistent, and the transaction can be committed. 將呼叫放在using區塊中的最後一個語句是很好的作法。It is very good practice to put the call as the last statement in the using block.

如需如何使用此方法的詳細資訊,請參閱使用交易範圍來執行隱含交易主題。For more information on how this method is used, see the Implementing An Implicit Transaction Using Transaction Scope topic.

無法呼叫這個方法會中止交易,因為交易管理員將此視為系統失敗,或在交易範圍內擲回例外狀況。Failing to call this method aborts the transaction, because the transaction manager interprets this as a system failure, or exceptions thrown within the scope of transaction. 不過,您也應該注意,呼叫這個方法並不保證會認可交易。However, you should also note that calling this method does not guarantee a commit of the transaction. 這只是將您的狀態告知異動管理員的方式。It is merely a way of informing the transaction manager of your status. 呼叫這個方法之後,您就無法再透過Current屬性存取環境交易,而且嘗試這麼做會導致擲回例外狀況。After calling this method, you can no longer access the ambient transaction via the Current property, and trying to do so results in an exception being thrown.

當物件建立交易時,資源管理員之間的認可實際End Using工作會在語句中發生。 TransactionScopeThe actual work of commit between the resources manager happens at the End Using statement if the TransactionScope object created the transaction. 如果該物件沒有建立交易,則每當 Commit 物件的擁有者呼叫 CommittableTransaction 時,便會發生認可。If it did not create the transaction, the commit occurs whenever Commit is called by the owner of the CommittableTransaction object. 此時,交易管理員會呼叫資源管理員,並根據TransactionScope物件上是否呼叫這個方法來通知它們認可或復原。At that point the Transaction Manager calls the resource managers and informs them to either commit or rollback, based on whether this method was called on the TransactionScope object.

適用於

另請參閱