Clerk 类
将事务性操作的记录写入日志。
**命名空间:**System.EnterpriseServices.CompensatingResourceManager
**程序集:**System.EnterpriseServices（在 system.enterpriseservices.dll 中）
语法
声明
Public NotInheritable Class Clerk
用法
Dim instance As Clerk
public sealed class Clerk
public ref class Clerk sealed
public final class Clerk
public final class Clerk
备注
每一 Clerk 都与补偿器关联，在事务的两阶段提交期间回调 Clerk 以执行操作。
示例
下面的代码示例演示如何使用该类。
' A CRM Worker
<Transaction()> _
Public Class Account
Inherits ServicedComponent
' A data member for the account file name.
Private filename As String
Public Property Filenam() As String
Get
Return Filename
End Get
Set(ByVal value As String)
filename = Value
End Set
End Property
' A boolean data member that determines whether to commit or abort the transaction.
Private commit As Boolean
Public Property AllowCommit() As Boolean
Get
Return commit
End Get
Set
commit = value
End Set
End Property
' Debit the account,
Public Sub DebitAccount(ByVal ammount As Integer)
' Create a new clerk using the AccountCompensator class.
Dim clerk As New Clerk(GetType(AccountCompensator), "An account transaction compensator", CompensatorOptions.AllPhases)
' Create a record of previous account status, and deliver it to the clerk.
Dim balance As Integer = AccountManager.ReadAccountBalance(Filenam)
Dim record(1) As [Object]
record(0) = filename
record(1) = balance
clerk.WriteLogRecord(record)
clerk.ForceLog()
' Perform the transaction
balance -= ammount
AccountManager.WriteAccountBalance(filename, balance)
' Commit or abort the transaction
If commit Then
ContextUtil.SetComplete()
Else
ContextUtil.SetAbort()
End If
End Class 'Account
// A CRM Worker
[Transaction]
public class Account : ServicedComponent
{
// A data member for the account file name.
private string filename;
public string Filename
{
get
{
return(filename);
}
set
{
filename = value;
}
}
// A boolean data member that determines whether to commit or abort the transaction.
private bool commit;
public bool AllowCommit
{
get
{
return(commit);
}
set
{
commit = value;
}
}
// Debit the account,
public void DebitAccount (int ammount)
{
// Create a new clerk using the AccountCompensator class.
Clerk clerk = new Clerk(typeof(AccountCompensator),
"An account transaction compensator", CompensatorOptions.AllPhases);
// Create a record of previous account status, and deliver it to the clerk.
int balance = AccountManager.ReadAccountBalance(filename);
Object[] record = new Object[2];
record[0] = filename;
record[1] = balance;
clerk.WriteLogRecord(record);
clerk.ForceLog();
// Perform the transaction
balance -= ammount;
AccountManager.WriteAccountBalance(filename, balance);
// Commit or abort the transaction
if (commit)
{
ContextUtil.SetComplete();
}
else
{
ContextUtil.SetAbort();
}
}
}
// A CRM Worker
[Transaction]
public ref class Account : public ServicedComponent
{
// A data member for the account file name.
private:
String^ filenameValue;
public:
property String^ Filename
{
String^ get()
{
return filenameValue;
}
void set( String^ value )
{
filenameValue = value;
}
}
// A boolean data member that determines whether to commit or abort the
// transaction.
private:
bool allowCommitValue;
public:
property bool AllowCommit
{
bool get()
{
return allowCommitValue;
}
void set( bool value )
{
allowCommitValue = value;
}
}
// Debit the account,
public:
void DebitAccount(int amount)
{
// Create a new clerk using the AccountCompensator class.
Clerk^ clerk = gcnew Clerk(AccountCompensator::typeid,
"An account transaction compensator", CompensatorOptions::AllPhases);
// Create a record of previous account status, and deliver it to the
// clerk.
int balance = ReadAccountBalance(Filename);
array<Object^>^ record = gcnew array<Object^>(2);
record[0] = Filename;
record[1] = balance;
clerk->WriteLogRecord(record);
clerk->ForceLog();
// Perform the transaction
balance -= amount;
Console::WriteLine("{0}: {1}", Filename, balance);
WriteAccountBalance(Filename, balance);
// Commit or abort the transaction
if (AllowCommit)
{
ContextUtil::SetComplete();
}
else
{
ContextUtil::SetAbort();
}
}
};
// A CRM Worker
/** @attribute Transaction()
*/
public class Account extends ServicedComponent
{
// A data member for the account file name.
/** @property
*/
private String fileName;
public String get_fileName()
{
return fileName;
} //get_fileName
public void set_fileName(String value)
{
fileName = value;
} //set_fileName
// A boolean data member that determines whether to commit or
// abort the transaction.
private boolean commit;
/** @property
*/
public boolean get_AllowCommit()
{
return commit;
} //get_AllowCommit
/** @property
*/
public void set_AllowCommit(boolean value)
{
commit = value;
} //set_AllowCommit
// Debit the account,
public void DebitAccount(int ammount)
{
// Create a new clerk using the AccountCompensator class.
Clerk clerk = new Clerk(AccountCompensator.class.ToType(),
"An account transaction compensator",
CompensatorOptions.AllPhases);
// Create a record of previous account status, and deliver
// it to the clerk.
Console.WriteLine("filename = " + fileName);
int balance = AccountManager.ReadAccountBalance(fileName);
Object record[] = new Object[2];
record.set_Item(0, fileName);
record.set_Item(1,(Int32)balance);
clerk.WriteLogRecord(record);
clerk.ForceLog();
// Perform the transaction
balance -= ammount;
AccountManager.WriteAccountBalance(fileName, balance);
// Commit or abort the transaction
if (commit) {
ContextUtil.SetComplete();
}
else {
ContextUtil.SetAbort();
}
} //DebitAccount
} //Account
下面的代码示例演示对应的 Compensator 类。
Imports System
Public Class CrmClient
Public Shared Sub Main()
' Create a new account object. The object is created in a COM+ server application.
Dim account As New Account()
' Transactionally debit the account.
Try
account.Filenam = System.IO.Path.GetFullPath("JohnDoe")
account.AllowCommit = True
account.DebitAccount(3)
Finally
account.Dispose()
End Try
End Sub 'Main
End Class 'CrmClient
using System;
public class CrmClient
{
public static void Main ()
{
// Create a new account object. The object is created in a COM+ server application.
Account account = new Account();
// Transactionally debit the account.
try
{
account.Filename = System.IO.Path.GetFullPath("JohnDoe");
account.AllowCommit = true;
account.DebitAccount(3);
}
finally
{
account.Dispose();
}
}
}
#using "System.EnterpriseServices.dll"
using namespace System;
[assembly: System::Reflection::AssemblyKeyFile("CrmServer.key")];
int main ()
{
// Create a new account object. The object is created in a COM+ server application.
Account^ account = gcnew Account();
// Transactionally debit the account.
try
{
account->Filename = System::IO::Path::GetFullPath("JohnDoe");
account->AllowCommit = true;
account->DebitAccount(3);
}
finally
{
delete account;
}
}
import System.*;
public class CrmClient
{
public static void main(String[] args)
{
// Create a new account object. The object is created in a COM+
// server application.
Account account = new Account();
// Transactionally debit the account.
try {
account.set_fileName(System.IO.Path.GetFullPath("JohnDoe"));
account.set_AllowCommit(true);
account.DebitAccount(3);
}
finally {
account.Dispose();
}
} //main
} //CrmClient
继承层次结构
System.Object
System.EnterpriseServices.CompensatingResourceManager.Clerk
线程安全
此类型的任何公共静态（Visual Basic 中的 Shared）成员都是线程安全的，但不保证所有实例成员都是线程安全的。
平台
Windows 98、Windows 2000 SP4、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、1.1、1.0
请参见
参考
Clerk 成员
System.EnterpriseServices.CompensatingResourceManager 命名空间