TransactionScope.Dispose 方法

public:
 virtual void Dispose();

public void Dispose ();

abstract member Dispose : unit -> unit
override this.Dispose : unit -> unit

Public Sub Dispose ()

實作

範例

下列範例示範如何使用 TransactionScope 類別來定義程式碼區塊，以參與交易。

// 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

呼叫這個方法會標示交易範圍的結尾。 TransactionScope如果物件已建立交易並在 Complete 範圍上呼叫， TransactionScope 則物件會在呼叫這個方法時嘗試認可交易。 在此情況下，這個方法會封鎖直到交易處理的第一個階段完成為止。 第一個階段會在交易中的所有資源管理員和登記都投票交易結果之後結束，而且 TransactionManager 已永久決定認可或中止交易。 處理的第二個階段一律是非同步。 因此，在不使用另一筆交易檢視此資料時，不保證只會立即從指定交易內認可資料。

使用 C# using 建構可確保即使發生例外狀況，仍會呼叫此方法。 在呼叫這個方法後發生的例外狀況不太可能會影響異動。 這個方法也會將環境交易還原至其原始狀態。 TransactionAbortedException如果未實際認可交易，則會擲回 。

因為這個方法會封鎖直到交易處理的第一個階段完成為止，所以在 Windows Form (WinForm) 應用程式中使用此方法時，您應該非常小心，或可能發生死結。 例如，如果您在一個 WinForm Control 事件內呼叫這個方法 (，請按一下按鈕) ，並使用同步 Invoke 方法來指示控制項執行某些 UI 工作 (，例如，在處理交易時變更色彩) ，就會發生死結。 這是因為 方法 Invoke 是同步的，並封鎖背景工作執行緒，直到 UI 執行緒完成其作業為止。 不過，在我們的案例中，UI 執行緒也會等待背景工作執行緒認可交易。 結果是，沒有任何能夠繼續，範圍會無限期等候認可完成。 您應該盡可能使用 ，而不是盡可能使用 BeginInvokeInvoke ，因為它是非同步，因此較不容易死結。

如需如何使用此方法的詳細資訊，請參閱 使用交易範圍實作隱含交易 主題。

適用於

另請參閱

• 使用交易範圍實作隱含交易