NET Framework 类库
TransactionScope 类
注意：此类在 .NET Framework 2.0 版中是新增的。
使代码块成为事务性代码。无法继承此类。
命名空间:System.Transactions
程序集:System.Transactions（在 system.transactions.dll 中）
语法
Visual Basic（声明）
Public NotInheritable Class TransactionScope
Implements IDisposable
Visual Basic（用法）
Dim instance As TransactionScope
C#
public sealed class TransactionScope : IDisposable
C++
public ref class TransactionScope sealed : IDisposable
J#
public final class TransactionScope implements IDisposable
JScript
public final class TransactionScope implements IDisposable
备注
System.Transactions 基础结构既提供了基于 Transaction 类的显式编程模型，也提供了使用 TransactionScope 类的隐式编程模型，在后一种模型中，事务由该基础结构自动管理。
重要事项：
建议使用 TransactionScope 类创建隐式事务，以便自动为您管理环境事务上下文。对于需要跨多个函数调用或多个线程调用使用相同事务的应用程序，您还应该使用 TransactionScope 和 DependentTransaction 类。有关此模型的更多信息，请参见 使用事务范围实现隐式事务 主题。有关编写事务性应用程序的更多信息，请参见 编写事务性应用程序。
在通过 new 语句实例化 TransactionScope 时，事务管理器将确定要参与哪个事务。一经确定，此范围将始终参与该事务。此决策基于两个因素：是否存在环境事务以及构造函数中 TransactionScopeOption 参数的值。环境事务是在其中执行您的代码的事务。通过调用 Transaction 类的 Current 静态属性可获取对环境事务的引用。有关如何使用此参数的更多信息，请参见 使用事务范围实现隐式事务 主题的“事务流管理”一节。
如果在事务范围中（即从初始化 TransactionScope 对象到调用其 Dispose 方法之间）未发生异常，则允许该范围所参与的事务继续。如果事务范围中的确发生了异常，它所参与的事务将回滚。
当应用程序完成它要在一个事务中执行的所有工作以后，您应当只调用 Complete 方法一次，以通知事务管理器可以接受提交事务。未能调用此方法将中止该事务。
对 Dispose 方法的调用标志着该事务范围的结束。在调用此方法之后发生的异常不会影响该事务。
如果在范围中修改 Current 的值，则会在调用 Dispose 时引发异常。但是，在该范围结束时，先前的值将被还原。此外，如果在创建事务的事务范围内对 Current 调用 Dispose，则该事务将在相应范围末尾处中止。
示例
下面的示例演示如何使用 TransactionScope 类定义代码块以参与事务。
Visual Basic 复制代码
' 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 RDBMS such as Oracle
' 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
' 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)
Try
' 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)
Try
' 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)
Catch ex As Exception
' Display information that command2 failed.
writer.WriteLine("returnValue for command2: {0}", returnValue)
writer.WriteLine("Exception Message2: {0}", ex.Message)
End Try
End Using
Catch ex As Exception
' Display information that command1 failed.
writer.WriteLine("returnValue for command1: {0}", returnValue)
writer.WriteLine("Exception Message1: {0}", ex.Message)
End Try
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
' The returnValue is greater than 0 if the transaction committed.
If returnValue > 0 Then
writer.WriteLine("Transaction was committed.")
Else
' You could write additional business logic here, for example, you can notify the caller
' by throwing a TransactionAbortedException, or logging the failure.
writer.WriteLine("Transaction rolled back.")
End If
' Display messages.
Console.WriteLine(writer.ToString())
Return returnValue
End Function
C# 复制代码
// 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 RDBMS such as Oracle
// 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();
// 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))
{
try
{
// 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))
try
{
// 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);
}
catch (Exception ex)
{
// Display information that command2 failed.
writer.WriteLine("returnValue for command2: {0}", returnValue);
writer.WriteLine("Exception Message2: {0}", ex.Message);
}
}
catch (Exception ex)
{
// Display information that command1 failed.
writer.WriteLine("returnValue for command1: {0}", returnValue);
writer.WriteLine("Exception Message1: {0}", ex.Message);
}
}
// The Complete method commits the transaction. If an exception has been thrown,
// Complete is not called and the transaction is rolled back.
scope.Complete();
}
// The returnValue is greater than 0 if the transaction committed.
if (returnValue > 0)
{
writer.WriteLine("Transaction was committed.");
}
else
{
// You could write additional business logic here, for example, you can notify the caller
// by throwing a TransactionAbortedException, or logging the failure.
writer.WriteLine("Transaction rolled back.");
}
// Display messages.
Console.WriteLine(writer.ToString());
return returnValue;
}
继承层次结构
System.Object
System.Transactions.TransactionScope
线程安全
该类型对于多线程操作是安全的。
平台
Windows 98、Windows 2000 SP4、Windows Millennium Edition、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition
.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。
版本信息
.NET Framework
受以下版本支持：2.0