TransactionScope.Dispose TransactionScope.Dispose TransactionScope.Dispose TransactionScope.Dispose Method

定義

トランザクション スコープを終了します。Ends the transaction scope.

public:
 virtual void Dispose();
public void Dispose ();
abstract member Dispose : unit -> unit
override this.Dispose : unit -> unit
Public Sub Dispose ()

実装

次の例は、クラスを使用TransactionScopeして、トランザクションに参加するコードのブロックを定義する方法を示しています。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

注釈

このメソッドを呼び出すと、トランザクションスコープの終了がマークされます。Calling this method marks the end of the transaction scope. オブジェクトによってCompleteトランザクションが作成され、スコープで呼び出されTransactionScopeた場合、このメソッドが呼び出されると、オブジェクトはトランザクションのコミットを試みます。 TransactionScopeIf the TransactionScope object created the transaction and Complete was called on the scope, the TransactionScope object attempts to commit the transaction when this method is called. この場合、このメソッドは、トランザクション処理の最初のフェーズが完了するまでブロックします。In this case, this method blocks until the first phase of transaction processing is complete. 最初のフェーズは、トランザクション内のすべてのTransactionManagerリソースマネージャーと参加リストがトランザクションの結果に投票し、永続的にがトランザクションのコミットまたは中止を決定した後に終了します。The first phase ends after all resource managers and enlistments in the transaction have voted on the transaction outcome and the TransactionManager has durably decided to commit or abort the transaction. 処理の2番目のフェーズは常に非同期です。The second phase of processing is always asynchronous. そのため、このデータを表示するために別のトランザクションを使用しない場合、特定のトランザクション内からコミットされたばかりのデータをすぐに使用できる保証はありません。Therefore, there is no guarantee that data just committed from within a given transaction will be immediately available afterwards when not using another transaction to view this data.

using構築を使用C#すると、例外が発生した場合でもこのメソッドが呼び出されるようになります。The use of the C# using construction ensures that this method is called even if an exception occurs. このメソッドの呼び出し後に発生した例外は、トランザクションに影響しない場合があります。Exceptions that occur after calling this method may not affect the transaction. このメソッドは、アンビエントトランザクションを元の状態に復元することもできます。This method also restores the ambient transaction to it original state. トランザクションTransactionAbortedExceptionが実際にコミットされていない場合は、がスローされます。A TransactionAbortedException is thrown if the transaction is not actually committed.

このメソッドは、トランザクション処理の最初のフェーズが完了するまでブロックするので、Windows フォーム (WinForm) アプリケーションでこのメソッドを使用する場合は細心の注意が必要です。または、デッドロックが発生する可能性があります。Because this method blocks until the first phase of transaction processing is complete, you should be extremely careful when using this method in a Windows Form (WinForm) application, or a deadlock can occur. 1つの WinForm コントロールイベント内でこのメソッドを呼び出し (ボタンをクリックするなど)、同期Invokeメソッドを使用して、トランザクションの処理中にいくつかの UI タスク (色の変更など) を実行するようコントロールに指示する場合は、デッドロックが発生します。If you call this method inside one WinForm Control event (for example, clicking a button), and use the synchronous Invoke method to direct the control to perform some UI tasks (for example, changing colors) in the middle of processing the transaction, a deadlock will happen. これは、 Invokeメソッドが同期され、UI スレッドがジョブを完了するまでワーカースレッドがブロックされるためです。This is because the Invoke method is synchronous and blocks the worker thread until the UI thread finishes its job. ただし、このシナリオでは、UI スレッドもワーカースレッドがトランザクションをコミットするのを待機しています。However, in our scenario, the UI thread is also waiting for the worker thread to commit the transaction. 結果として、何も続行できず、コミットが終了するまでスコープが無期限に待機することになります。The result is that none is able to proceed and the scope waits indefinitely for the Commit to finish. 非同期であるBeginInvokeため、 Invokeデッドロックが発生しにくくなるため、可能な限りを使用する必要があります。You should use BeginInvoke rather than Invoke wherever possible, because it is asynchronous and thus less prone to deadlock.

このメソッドの使用方法の詳細については、「トランザクションスコープを使用した暗黙のトランザクションの実装」を参照してください。For more information on how this method is used, see the Implementing An Implicit Transaction Using Transaction Scope topic.

適用対象

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