C# 如何编辑文件的摘要信息

 /*pls visit this article
  * * http://msdn2.microsoft.com/en-us/library/aa380328.aspx
  * To open an existing file, use the StgOpenStorageEx function instead.
  notice:
 Applications written for Windows 2000, Windows Server 2003 and Windows XP must use StgCreateStorageEx rather than StgCreateDocfile to take advantage of the enhanced Windows 2000 and Windows XP Structured Storage features.
  * 
 
 
  */
 
 
 using System;
 using System.Collections.Generic;
 using System.Text;
 using StructuredStorageWrapper;
 
 
 namespace WindowsApplication8
 {
     class FileSummary
     {
         public static void SetProperty(string filename,string msg , SummaryPropId summaryType)
         {
             // first you need to either create or open a file and its 
             // property set stream 
             //申明接口(指针)
             IPropertySetStorage propSetStorage = null;
             //com 组件的 clsid 参见IPropertySetStorage定义
             Guid IID_PropertySetStorage = new
 Guid("0000013A-0000-0000-C000-000000000046");
 
             //Applications written for Windows 2000, Windows Server 2003 and Windows XP must use StgCreateStorageEx rather than StgCreateDocfile to take advantage of the enhanced Windows 2000 and Windows XP Structured Storage features            
             uint hresult = ole32.StgOpenStorageEx(
                 filename,
                 (int)(STGM.SHARE_EXCLUSIVE | STGM.READWRITE),
                 (int)STGFMT.FILE,
                 0,
                 (IntPtr)0,
                 (IntPtr)0,
                 ref IID_PropertySetStorage,
                 ref propSetStorage); //返回指针
 
 
             // next you need to create or open the Summary Information property set 
             Guid fmtid_SummaryProperties = new
 Guid("F29F85E0-4FF9-1068-AB91-08002B27B3D9");
             IPropertyStorage propStorage = null;
 
 
             hresult = propSetStorage.Create(
                 ref fmtid_SummaryProperties,
                 (IntPtr)0,
                 (int)PROPSETFLAG.DEFAULT,
                 (int)(STGM.CREATE | STGM.READWRITE |
 STGM.SHARE_EXCLUSIVE),
                 ref propStorage);
 
 
             // next, you assemble a property descriptor for the property you 
             // want to write to, in our case the Comment property 
             PropSpec propertySpecification = new PropSpec();
             propertySpecification.ulKind = 1;
             propertySpecification.Name_Or_ID = new
 IntPtr((int)summaryType);
 
 
             //now, set the value you want in a property variant 
             PropVariant propertyValue = new PropVariant();
             propertyValue.FromObject(msg);
 
 
             // Simply pass the property spec and its new value to the WriteMultiple 
             // method and you‘re almost done 
             propStorage.WriteMultiple(1, ref propertySpecification, ref 
 propertyValue, 2);
 
 
             // the only thing left to do is commit your changes.  Now you‘re done! 
             hresult = propStorage.Commit((int)STGC.DEFAULT);
 
 
             //下面的很关键,如何关闭一个非托管的指针,如果不关闭,则本程序不关闭,文件被锁定!
             System.Runtime.InteropServices.Marshal.ReleaseComObject(propSetStorage);
             propSetStorage = null;
             GC.Collect();
         }
     }
 }
 
 
把ole32一些方法进行COM封装
 using System;
 using System.Text;
 using System.Runtime.InteropServices;
 
 
 namespace StructuredStorageWrapper
 {
     public enum SummaryPropId : int
     {
         Title = 0x00000002,
         Subject = 0x00000003,
         Author = 0x00000004,
         Keywords = 0x00000005,
         Comments = 0x00000006,
         Template = 0x00000007,
         LastSavedBy = 0x00000008,
         RevisionNumber = 0x00000009,
         TotalEditingTime = 0x0000000A,
         LastPrinted = 0x0000000B,
         CreateDateTime = 0x0000000C,
         LastSaveDateTime = 0x0000000D,
         NumPages = 0x0000000E,
         NumWords = 0x0000000F,
         NumChars = 0x00000010,
         Thumbnail = 0x00000011,
         AppName = 0x00000012,
         Security = 0x00000013
     }
 
 
     public enum STGC : int
     {
         DEFAULT = 0,
         OVERWRITE = 1,
         ONLYIFCURRENT = 2,
         DANGEROUSLYCOMMITMERELYTODISKCACHE = 4,
         CONSOLIDATE = 8
     }
 
 
     public enum PROPSETFLAG : int
     {
         DEFAULT = 0,
         NONSIMPLE = 1,
         ANSI = 2,
         UNBUFFERED = 4,
         CASE_SENSITIVE = 8
     }
 
     
     public enum STGM : int
     {
         READ = 0x00000000,
         WRITE = 0x00000001,
         READWRITE = 0x00000002,
         SHARE_DENY_NONE = 0x00000040,
         SHARE_DENY_READ = 0x00000030,
         SHARE_DENY_WRITE = 0x00000020,
         SHARE_EXCLUSIVE = 0x00000010,
         PRIORITY = 0x00040000,
         CREATE = 0x00001000,
         CONVERT = 0x00020000,
         FAILIFTHERE = 0x00000000,
         DIRECT = 0x00000000,
         TRANSACTED = 0x00010000,
         NOSCRATCH = 0x00100000,
         NOSNAPSHOT = 0x00200000,
         SIMPLE = 0x08000000,
         DIRECT_SWMR = 0x00400000,
         DELETEONRELEASE = 0x04000000
     }
 
 
     public enum STGFMT : int
     {
         STORAGE = 0,
         FILE = 3,
         ANY = 4,
         DOCFILE = 5
     }
 
 
     [StructLayout(LayoutKind.Explicit, Size = 8, CharSet = CharSet.Unicode)]
     public struct PropSpec
     {
         [FieldOffset(0)]
         public int ulKind;
         [FieldOffset(4)]
         public IntPtr Name_Or_ID;
     }
 
 
     [StructLayout(LayoutKind.Explicit, Size = 16)]
     public struct PropVariant
     {
         [FieldOffset(0)]
         public short variantType;
         [FieldOffset(8)]
         public IntPtr pointerValue;
         [FieldOffset(8)]
         public byte byteValue;
         [FieldOffset(8)]
         public long longValue;
 
 
         public void FromObject(object obj)
         {
             if (obj.GetType() == typeof(string))
             {
                 this.variantType = (short)VarEnum.VT_LPWSTR;
                 this.pointerValue = Marshal.StringToHGlobalUni((string)obj);
             }
         }
     }
 
 
     [ComVisible(true), ComImport(),
     Guid("0000013A-0000-0000-C000-000000000046"),
     InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
     public interface IPropertySetStorage
     {
         uint Create(
             [In, MarshalAs(UnmanagedType.Struct)] ref System.Guid rfmtid,
       [In] IntPtr pclsid,
       [In] int grfFlags,
             [In] int grfMode,
       ref IPropertyStorage propertyStorage);
 
 
         int Open(
             [In, MarshalAs(UnmanagedType.Struct)] ref System.Guid rfmtid,
             [In] int grfMode,
                   [Out] IPropertyStorage propertyStorage);
     }
 
 
     [ComVisible(true), ComImport(),
     Guid("00000138-0000-0000-C000-000000000046"),
     InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
     public interface IPropertyStorage
     {
         int ReadMultiple(
             uint numProperties,
             PropSpec[] propertySpecifications,
             PropVariant[] propertyValues);
 
 
         int WriteMultiple(
             uint numProperties,
             [MarshalAs(UnmanagedType.Struct)] ref PropSpec
 propertySpecification,
             ref PropVariant propertyValues,
             int propIDNameFirst);
 
 
         uint Commit(
             int commitFlags);
     }
 
 
     public enum HResults : uint
     {
         S_OK = 0,
         STG_E_FILEALREADYEXISTS = 0x80030050
     }
 
 
     public class ole32
     {
         [StructLayout(LayoutKind.Explicit, Size = 12,
 CharSet = CharSet.Unicode)]
         public struct STGOptions
         {
             [FieldOffset(0)]
             ushort usVersion;
             [FieldOffset(2)]
             ushort reserved;
             [FieldOffset(4)]
             uint uiSectorSize;
             [FieldOffset(8), MarshalAs(UnmanagedType.LPWStr)]
             string
 pwcsTemplateFile;
         }
 
 
         [DllImport("ole32.dll", CharSet = CharSet.Unicode)]
         public static extern uint StgCreateStorageEx(
             [MarshalAs(UnmanagedType.LPWStr)] string name,
             int accessMode, int storageFileFormat, int fileBuffering,
             IntPtr options, IntPtr reserved, ref System.Guid riid,
             [MarshalAs(UnmanagedType.Interface)] ref IPropertySetStorage
 propertySetStorage);
 
 
         [DllImport("ole32.dll", CharSet = CharSet.Unicode)]
         public static extern uint StgOpenStorageEx(
             [MarshalAs(UnmanagedType.LPWStr)] string name,
             int accessMode, int storageFileFormat, int fileBuffering,
             IntPtr options, IntPtr reserved, ref System.Guid riid,
             [MarshalAs(UnmanagedType.Interface)] ref IPropertySetStorage
 propertySetStorage);
     }
 
 
 
 }