支持XML Web服務的事務利用公共語言運行期中的支持，其是基于Microsoft Transaction Server ( MTS)和COM+ Services中相同的分布式事務模型。該模型基于明確的判斷一個對象是否參與一個事務，而不是編寫特定的代碼用來處理委托和回調一個事務。對于一個使用ASP.net創(chuàng)建的XML Web服務，你可以通過設置其應用到一個XML Web服務方法上的WebMethod屬性的TransactionOption屬性來聲明一個XML Web服務的事務行為。如果該XML Web服務方法執(zhí)行的時候拋出一個異常，那么該事務自動地結束；相反，如果沒有發(fā)生異常，該事務自動委托。
WebMethod屬性的TransactionOption屬性規(guī)定一個XML Web服務方法如何參與一個事務。雖然這個聲明級別表示一個事務邏輯，但是它是消除實際事務的一個步驟。當事物對象訪問數(shù)據(jù)源（如數(shù)據(jù)庫或消息隊列）時實際事務產生。關聯(lián)該對象的事務自動流向適當?shù)馁Y源管理程序。像.NET Framework Data Provider（用于SQL Server或OLE DB）這樣的.NET Framework數(shù)據(jù)提供者在對象的上下文中查找事務并通過Distributed Transaction Coordinator (DTC，分布式事務協(xié)調程序)編目事務。全部的事務自動產生。
XML Web服務方法只能參與一個作為新事務的根的事務。作為一個新事務的根，所有的與資源管理器（像運行Microsoft SQL Server、Microsoft Message Queuing和Microsoft Host Integration Server的服務器）的相互作用維護需要運行健壯的分布式應用程序的ACID性質。調用其他的XML Web服務方法的XML Web服務方法參與不同的事務，因為事務不流經XML Web服務方法。
使用來自XML Web服務方法的事務
聲明一個XML Web服務。
[C#]
＜%@ WebService Language="C#" Class="Orders" %＞
[Visual Basic]
＜%@ WebService Language="VB" Class="Orders" %＞
把一個匯編指令加到System.EntERPriseServices上。
＜%@ Assembly name="System.EnterpriseServices,Version=1.0.3300.0,Culture=neutral,PublicKeyToken=b03f5f7f11d50a3a" %＞
添加引用到System.Web.Services和System.EnterpriseServices域名空間。
[C#]
using System.Web.Services;
using System.EnterpriseServices;
[Visual Basic]
Imports System.Web.Services
Imports System.EnterpriseServices
聲明一個XML Web服務方法，設置WebMethod屬性的TransactionOption屬性為TransactionOption.RequiresNew。
[C#]
[ WebMethod(TransactionOption=TransactionOption.RequiresNew)]
public int DeleteAuthor(string lastName)
[Visual Basic]
＜ WebMethod(TransactionOption:=TransactionOption.RequiresNew)＞ _
Public Function DeleteAuthor(lastName As String) As Integer
下面的代碼示例顯示一個使用單個XML Web服務方法的XML Web服務，調用DeleteDatabase。這個XML Web服務方法執(zhí)行一個事務范圍內的數(shù)據(jù)庫操作。如果該數(shù)據(jù)庫操作拋出一個異常，該事務自動地停止；否則，該事務自動地委托。
[C#]
＜%@ WebService Language="C#" Class="Orders" %＞
＜%@ Assembly name="System.EnterpriseServices,Version=1.0.3300.0,Culture=neutral,PublicKeyToken=b03f5f7f11d50a3a" %＞
using System;
using System.Data;
using System.Data.SqlClient;
using System.Web.Services;
using System.EnterpriseServices;
public class Orders : WebService
{
[ WebMethod(TransactionOption=TransactionOption.RequiresNew)]
public int DeleteAuthor(string lastName)
{
String deleteCmd = "DELETE FROM authors WHERE au_lname='" +
lastName + "'" ;
String exceptionCausingCmdSQL = "DELETE FROM NonExistingTable WHERE
au_lname='" + lastName + "'" ;
SqlConnection sqlConn = new SqlConnection(
"Persist Security Info=False;Integrated Security=SSPI;database=pubs;server=myserver");
SqlCommand deleteCmd = new SqlCommand(deleteCmdSQL,sqlConn);
SqlCommand exceptionCausingCmd = new
SqlCommand(exceptionCausingCmdSQL,sqlConn);
// This command should execute proPerly.
deleteCmd.Connection.Open();
deleteCmd.ExecuteNonQuery();
// This command results in an exception, so the first command is
// automatically rolled back. Since the XML Web Service method is
// participating in a transaction, and an exception occurs, ASP.NET
// automatically aborts the transaction. The deleteCmd that
// executed properly is rolled back.
int cmdResult = exceptionCausingCmd.ExecuteNonQuery();
sqlConn.Close();
return cmdResult;
}
}
[Visual Basic]
＜%@ WebService Language="VB" Class="Orders" %＞
＜%@ assembly name="System.EnterpriseServices" %＞
Imports System
Imports System.Data
Imports System.Data.SqlClient
Imports System.Web.Services
Imports System.Web.Util
Imports System.EnterpriseServices
Public Class Orders
＜WebMethod(TransactionOption:=TransactionOption.RequiresNew)＞ _
Public Function DeleteAuthor (lastName as String) as Integer
Dim deleteCmdSQL As String = "DELETE FROM authors WHERE au_lname='" + _
lastName + "'"
Dim exceptionCausingCmdSQL As String = "DELETE FROM " + _
"NonExistingTable WHERE au_lname='" + lastName + "'"
Dim sqlConn As SqlConnection = New SqlConnection( _
"Persist Security Info=False;Integrated Security=SSPI;database=pubs;server=myserver")
Dim deleteCmd As SqlCommand = New SqlCommand(deleteCmdSQL,sqlConn)
Dim exceptionCausingCmd As SqlCommand = New _
SqlCommand(exceptionCausingCmdSQL,sqlConn)
' This command should execute properly.
deleteCmd.Connection.Open()
deleteCmd.ExecuteNonQuery()
' This command results in an exception, so the first command is
' automatically rolled back. Since the XML Web service method is
' participating in a transaction, and an exception occurs, ASP.NET
' automatically aborts the transaction. The deleteCmd that
' executed properly is rolled back.
Dim cmdResult As Integer = exceptionCausingCmd.ExecuteNonQuery()
sqlConn.Close()
Return cmdResult
End Function
End Class
WebMethod屬性的TransactionOption屬性規(guī)定一個XML Web服務方法如何參與一個事務。雖然這個聲明級別表示一個事務邏輯，但是它是消除實際事務的一個步驟。當事物對象訪問數(shù)據(jù)源（如數(shù)據(jù)庫或消息隊列）時實際事務產生。關聯(lián)該對象的事務自動流向適當?shù)馁Y源管理程序。像.NET Framework Data Provider（用于SQL Server或OLE DB）這樣的.NET Framework數(shù)據(jù)提供者在對象的上下文中查找事務并通過Distributed Transaction Coordinator (DTC，分布式事務協(xié)調程序)編目事務。全部的事務自動產生。
XML Web服務方法只能參與一個作為新事務的根的事務。作為一個新事務的根，所有的與資源管理器（像運行Microsoft SQL Server、Microsoft Message Queuing和Microsoft Host Integration Server的服務器）的相互作用維護需要運行健壯的分布式應用程序的ACID性質。調用其他的XML Web服務方法的XML Web服務方法參與不同的事務，因為事務不流經XML Web服務方法。
使用來自XML Web服務方法的事務
聲明一個XML Web服務。
[C#]
＜%@ WebService Language="C#" Class="Orders" %＞
[Visual Basic]
＜%@ WebService Language="VB" Class="Orders" %＞
把一個匯編指令加到System.EntERPriseServices上。
＜%@ Assembly name="System.EnterpriseServices,Version=1.0.3300.0,Culture=neutral,PublicKeyToken=b03f5f7f11d50a3a" %＞
添加引用到System.Web.Services和System.EnterpriseServices域名空間。
[C#]
using System.Web.Services;
using System.EnterpriseServices;
[Visual Basic]
Imports System.Web.Services
Imports System.EnterpriseServices
聲明一個XML Web服務方法，設置WebMethod屬性的TransactionOption屬性為TransactionOption.RequiresNew。
[C#]
[ WebMethod(TransactionOption=TransactionOption.RequiresNew)]
public int DeleteAuthor(string lastName)
[Visual Basic]
＜ WebMethod(TransactionOption:=TransactionOption.RequiresNew)＞ _
Public Function DeleteAuthor(lastName As String) As Integer
下面的代碼示例顯示一個使用單個XML Web服務方法的XML Web服務，調用DeleteDatabase。這個XML Web服務方法執(zhí)行一個事務范圍內的數(shù)據(jù)庫操作。如果該數(shù)據(jù)庫操作拋出一個異常，該事務自動地停止；否則，該事務自動地委托。
[C#]
＜%@ WebService Language="C#" Class="Orders" %＞
＜%@ Assembly name="System.EnterpriseServices,Version=1.0.3300.0,Culture=neutral,PublicKeyToken=b03f5f7f11d50a3a" %＞
using System;
using System.Data;
using System.Data.SqlClient;
using System.Web.Services;
using System.EnterpriseServices;
public class Orders : WebService
{
[ WebMethod(TransactionOption=TransactionOption.RequiresNew)]
public int DeleteAuthor(string lastName)
{
String deleteCmd = "DELETE FROM authors WHERE au_lname='" +
lastName + "'" ;
String exceptionCausingCmdSQL = "DELETE FROM NonExistingTable WHERE
au_lname='" + lastName + "'" ;
SqlConnection sqlConn = new SqlConnection(
"Persist Security Info=False;Integrated Security=SSPI;database=pubs;server=myserver");
SqlCommand deleteCmd = new SqlCommand(deleteCmdSQL,sqlConn);
SqlCommand exceptionCausingCmd = new
SqlCommand(exceptionCausingCmdSQL,sqlConn);
// This command should execute proPerly.
deleteCmd.Connection.Open();
deleteCmd.ExecuteNonQuery();
// This command results in an exception, so the first command is
// automatically rolled back. Since the XML Web Service method is
// participating in a transaction, and an exception occurs, ASP.NET
// automatically aborts the transaction. The deleteCmd that
// executed properly is rolled back.
int cmdResult = exceptionCausingCmd.ExecuteNonQuery();
sqlConn.Close();
return cmdResult;
}
}
[Visual Basic]
＜%@ WebService Language="VB" Class="Orders" %＞
＜%@ assembly name="System.EnterpriseServices" %＞
Imports System
Imports System.Data
Imports System.Data.SqlClient
Imports System.Web.Services
Imports System.Web.Util
Imports System.EnterpriseServices
Public Class Orders
＜WebMethod(TransactionOption:=TransactionOption.RequiresNew)＞ _
Public Function DeleteAuthor (lastName as String) as Integer
Dim deleteCmdSQL As String = "DELETE FROM authors WHERE au_lname='" + _
lastName + "'"
Dim exceptionCausingCmdSQL As String = "DELETE FROM " + _
"NonExistingTable WHERE au_lname='" + lastName + "'"
Dim sqlConn As SqlConnection = New SqlConnection( _
"Persist Security Info=False;Integrated Security=SSPI;database=pubs;server=myserver")
Dim deleteCmd As SqlCommand = New SqlCommand(deleteCmdSQL,sqlConn)
Dim exceptionCausingCmd As SqlCommand = New _
SqlCommand(exceptionCausingCmdSQL,sqlConn)
' This command should execute properly.
deleteCmd.Connection.Open()
deleteCmd.ExecuteNonQuery()
' This command results in an exception, so the first command is
' automatically rolled back. Since the XML Web service method is
' participating in a transaction, and an exception occurs, ASP.NET
' automatically aborts the transaction. The deleteCmd that
' executed properly is rolled back.
Dim cmdResult As Integer = exceptionCausingCmd.ExecuteNonQuery()
sqlConn.Close()
Return cmdResult
End Function
End Class