TransactionScope 类
定义
重要
一些信息与预发行产品相关，相应产品在发行之前可能会进行重大修改。 对于此处提供的信息，Microsoft 不作任何明示或暗示的担保。
使代码块成为事务性代码。 此类不能被继承。
public ref class TransactionScope sealed : IDisposablepublic sealed class TransactionScope : IDisposable[System.Runtime.Versioning.UnsupportedOSPlatform("browser")]
public sealed class TransactionScope : IDisposabletype TransactionScope = class
interface IDisposable[<System.Runtime.Versioning.UnsupportedOSPlatform("browser")>]
type TransactionScope = class
interface IDisposablePublic NotInheritable Class TransactionScope
Implements IDisposable- 继承
-
TransactionScope
- 属性
- 实现
示例
以下示例演示如何使用 TransactionScope 类定义代码块以参与事务。
// 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
注解
基础结构 System.Transactions 提供基于 Transaction 类的显式编程模型，以及使用 TransactionScope 类的隐式编程模型，其中事务由基础结构自动管理。
重要
建议使用 TransactionScope 类创建隐式事务，以便自动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同一事务的应用程序，还应使用 TransactionScope 和 DependentTransaction 类。 有关此模型的详细信息，请参阅 使用事务范围实现隐式事务 主题。 有关编写事务应用程序的详细信息，请参阅 编写事务性应用程序。
通过 new 语句实例化 后TransactionScope，事务管理器将确定要参与的事务。 一旦确定，该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。 环境事务是代码执行中的事务。 可通过调用 Transaction.Current 类的静态 Transaction 属性，获取对环境事务的引用。 有关如何使用此参数的详细信息，请参阅 使用事务范围实现隐式事务 主题的“事务流管理”部分。
如果事务范围 (（即，在对象的初始化 TransactionScope 和调用其 Dispose 方法) 之间）中未发生异常，则允许范围参与的事务继续进行。 如果在事务范围内确实发生异常，则会回滚它参与的事务。
当应用程序完成它想要在事务中执行的所有工作时，应仅调用 Complete 方法一次，以通知事务管理器可以接受提交事务。 未能调用此方法会中止事务。
对 方法的 Dispose 调用将标记事务范围的末尾。 在调用此方法之后所发生的异常不会影响事务。
如果在作用域内修改 的值 Current ，则在调用 时 Dispose 将引发异常。 但是，在作用域结束时，将还原上一个值。 此外，如果在创建事务的事务范围内调用 DisposeCurrent ，该事务会在作用域末尾中止。
构造函数
方法
| Complete() |
指示范围中的所有操作都已成功完成。 |
| Dispose() |
结束事务范围。 |
| Equals(Object) |
确定指定对象是否等于当前对象。 (继承自 Object) |
| GetHashCode() |
作为默认哈希函数。 (继承自 Object) |
| GetType() |
获取当前实例的 Type。 (继承自 Object) |
| MemberwiseClone() |
创建当前 Object 的浅表副本。 (继承自 Object) |
| ToString() |
返回表示当前对象的字符串。 (继承自 Object) |
适用于
线程安全性
此类型是线程安全的。
