transactedfile.cs

C#高级编程第6版随书源代码 值得下载

using System;
using System.IO;
using System.Transactions;
using Microsoft.Win32.SafeHandles;
using System.Security.Permissions;

namespace Wrox.ProCSharp.Transactions
{


   public static class TransactedFile
   {
      internal const short FILE_ATTRIBUTE_NORMAL = 0x80;
      internal const short INVALID_HANDLE_VALUE = -1;
      internal const uint GENERIC_READ = 0x80000000;
      internal const uint GENERIC_WRITE = 0x40000000;
      internal const uint CREATE_NEW = 1;
      internal const uint CREATE_ALWAYS = 2;
      internal const uint OPEN_EXISTING = 3;


      [FileIOPermission(SecurityAction.Demand, Unrestricted = true)]
      public static FileStream GetTransactedFileStream(string fileName)
      {
         IKernelTransaction ktx = (IKernelTransaction)
                 TransactionInterop.GetDtcTransaction(Transaction.Current);

         SafeTransactionHandle txHandle;
         ktx.GetHandle(out txHandle);

         SafeFileHandle fileHandle = NativeMethods.CreateFileTransacted(
             fileName, GENERIC_WRITE, 0,
             IntPtr.Zero, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL,
             IntPtr.Zero,
             txHandle, IntPtr.Zero, IntPtr.Zero);

         return new FileStream(fileHandle, FileAccess.Write);

      }
   }
}